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HOME OP THE RADFORD PUBLICATIONS, CHICAGO, ILLINOIS 

penter and Builder” and the -Cement World ” 










Radford’s 


Cyclopedia of 

Construction 


Carpentry, Building 

and 

Architecture 


A General Reference Work on 

MODERN BUILDING MATERIALS AND METHODS AND THEIR PRACTICAL AP 
PLICATION TO ALL FORMS OF CONSTRUCTION IN WOOD, STONE, BRICK, 
STEEL, AND CONCRETE; INCLUDING ALSO SUCH ALLIED BRANCHES 
OF THE STRUCTURAL FIELD AS HEATING AND VENTILATING, 
PLUMBING, ELECTRIC WIRING, PAINTING, CONTRACTS, SPECI¬ 
FICATIONS, ESTIMATING, STRUCTURAL DRAFTING. ETC. 

Based on the Practical Experience of a 

LARGE STAFF OF EXPERTS IN ACTUAL CONSTRUCTION WORK 


Illustrated 


TWELVE VOLUMES 



THE RADFORD ARCHITECTURAL COMPANY 

CHICAGO, ILL. 










Copyright, 1915 

BY 

THE RADFORD ARCHITECTURAL COMPANY 


AUG -2 19(5 


©CI.A401D56 

K^O f 



Radford’s 

Cyclopedia of Construction 


Prepared under the Supervision of 

WILLIAM A. RADFORD 

Editor-in-Chief 

President of the Radford Architectural Company, Chicago, Ill. 
Editor-in-Chief of the “American Carpenter and 
Builder” and the “ Cement World” 


ALFRED SIDNEY JOHNSON, A. M. f Ph. D. 

Editor in Charge 

Author of “The Materials and Manufacture of Concrete,” etc. 
Formerly Editor of “Current History.” Associate 
Editor of Numerous Standard Works 
of Reference 


Partial List of Authors and Collaborators 

JOHN P. BROOKS, M. S. 

Associate Professor of Civil Engineering, and Acting Head of 
Department of Civil Engineering, University of Illinois 


FRANK O. DUFOUR, C. E. 

Assistant Professor of Structural Engineering, University of Illin- 
nois 

Author of “Bridge Engineering,” “Roof Trusses,” etc. 


DAVID P. MORETON, B. S. 

Associate Professor of Electrical Engineering, Armour Institute 
of Technology 


ALFRED G. KING 

Consulting Engineer on Heating and Ventilating 
Author of “Practical Steam and Hot-Water Heating and Ventila¬ 
tion.” “Steam and Hot-Water Heating Charts,” “Practical 
Heating Illustrated,” etc. 

ERVIN KENISON, S. B. 

Assistant Professor of Mechanical Drawing and Descriptive 
Geometry, Massachusetts Institute of Technology 
Author of a Practical Textbook of Mechanical Drawing 





AUTHORS AND COLLABORATORS—(Continued) 

LOSING H. PROVINE, B. S. 

Instructor in Architectural Engineering, Department of Archi¬ 
tecture, University of Illinois 


THOMAS TAIT, C. E. 

Consulting Heating, Ventilating, and Sanitary Engineer 
Member American Society of Inspectors of Plumbing and Sanitary 
Engineers 

Member American Society of Heating and Ventilating Engineers 


BICHARD T. DANA 

Consulting Engineer 

Chief Engineer, Construction Service Company, New York, N. Y. 
Joint Author with Halbert P. Gillette of “Cost-Analysis Engi¬ 
neering” 

Member American Society of Civil Engineers 
Member American Institute of Mechanical Engineers 


WILLIAM A. RADFORD 

President, The Radford Architectural Company, Chicago, Ill. 
Editor-in-Chlef, “American Carpenter and Builder” and “Cement 
World” 

Author of “Practical Carpentry,” “The Steel Square,” etc. 


GEORGE W. ASHBY 

Architect 

Vice-President, The Radford Architectural Company, Chicago, Ill. 
CHARLES W. RADFORD 

Treasurer, The Radford Architectural Company, Chicago, Ill. 


CHARLES D. WARNER 

Editor “Cement World” and “Dealers Record.” 


BERNARD L. JOHNSON, B. S. 

Editor “American Carpenter and Builder” and “Woodworkers Re¬ 
view” 

Formerly Mechanical Engineer, Fitz-Hugh Luther Locomotive & 
Car Company, Chicago, III. 


E. L. HATFIELD 

General Manager, Cement World Company, Chicago, Ill. 


IRA S. GRIFFITH, A. B. 

Supervisor of Manual Training, Oak Park, Ill. 

Member Editorial Board, Western Drawing and Manual Training 
Association & 

Formerly Professor of Mathematics, Eureka College 
Author of “Essentials of Woodworking” 


AUTHORS AND COLLABORATORS—(Concluded) 

CHARLES EDWARD PAUL, S. B. 

Associate Professor of Mechanics, Armour Institute of Technology 
Member American Society of Mechanical Engineers 
Member American Society for Testing Materials 

EDWIN O. GREIFENIIAGEN, B. S., C. E. 

Office Engineer, Bridge and Building Department, Chicago, Mil¬ 
waukee & St. Paul Railway 

ALFRED W. WOODS 

Architect 

Inventor of “Wood’s Key to the Steel Square” 

Joint Author of “The Steel Square and Its Uses” 


WILLIAM REUTHER 

Expert on Modern Building Methods 


T. B. KIDNER 

Director of Manual Training and Household Science, Department 
of Education, Province of New Brunswick 
Fellow of the British Institute of Carpentry 


P. W. RATHBUN, B. S. 

Consulting Engineer 

Member American Society of Heating and Ventilating Engineers 


EDWARD HURST BROWN 

Editor “Painters’ Magazine” 


CHARLES P. RAWSON 

Chief Draftsman, The Radford Architectural Company, Chicago, Ill. 


I. P. HICKS 

Architect and Contractor 


Bibliography of Construction 

BEING A SELECTED LIST OF STANDARD WORKS COVERING VARIOUS POR¬ 
TIONS OF THE GENERAL FIELD OF CONSTRUCTION 

In addition to the vast store of up-to-date practical information 
never before published, the editors have embodied in the Cyclopedia 
of Construction the cream of the world’s best literature in this field, 
giving in condensed form the substance of everything essential in 
the experience of the past to enable the worker of the present to meet 
every problem likely to be met with under the conditions of ordinary 
practice. 

For the sake, however, of those who may be interested in pur¬ 
suing further study along various special lines, we furnish a list of 
important works that have appeared covering different portions of 
the field. 

In this connection, the editors wish to express their thanks to 
American manufacturers and dealers in the machinery and materials 
of construction, as well as to proprietors and patentees of various 
special mechanical devices and processes, for valuable data, illus¬ 
trations and suggestions. 


Authorities on Construction 

MANSFIELD MEEBIMAN, C. E., Ph. D. 

Professor of Civil Engineering, Lehigh University 
Author of Mechanics of Materials;” “Retaining Walls and Ma¬ 
sonry Dams; “Elements of Sanitary Engineering;” “A 
textbook on Roofs and Bridges,” etc. ° 

HALBEET P. GILLETTE 

Washington State Railroad Commission 
Author of Handbook of Cost Data for Contractors and Engineer ” 

JOHN C. TEAUTWINE 

Author of “The Civil Engineer’s Pocketbook” 

FEEDEE1CK W. TAYLOE, M. E., and SANFOED E. THOMPSON 
S. B., C. E. ' 

Authors of “A Treatise on Concrete, Plain and Reinforced” 
FEEDEBICK E. TUBNEAUBE, C. E., Dr. Eng. 

P®,® 1 * °. f College of Engineering, University of Wisconsin 
Joint Author of “Principles of Reinforced Concrete Construction •" 
theory and Practice of Modern Framed Structures,” etc ’ 

EDWAED GODFEEY 

Structural Engineer for Robert W. Hunt & Co 
Authoi’i I—“Concrete!” & 1 Engineerin s” (Book ' I-“Tables Book 

A. PEESCOTT FOLWELL 

Author n} I H2 lc,pal JournaI and Engineer” 

Authoi of Sewerage;” “Water-Supply Engineering,” etc. 


AUTHORITIES ON CONSTRUCTION 


IEA O. BAKER, C. E. 

Professor of Civil Engineering, University of Illinois 
Author of “A Treatise on Masonry Construction;” ‘‘Roads and 
Pavements,” etc. 

FRANK E. KIDDER, C. E., Ph. D. 

Author of “Architect’s and Builder’s Pocketbook ;” “Building Con¬ 
struction and Superintendence,” etc. 

CHARLES EVAN FOWLER, C. E. 

President, Pacific Northwestern Society of Engineers 
Author of “Ordinary Foundations” 

FRED T. HODGSON, ARCHITECT 

Author of “Modern Carpentry;” “Builder and Contractor’s Guide, 
etc. ' 


HENRY R. TOWNE 

Author of “Locks and Builders’ Hardware” 


HENRY N. OGDEN, C. E. 

Assistant Professor of Civil Engineering, Cornell University 

Author of “Sewer Construction” 

CHARLES E. GREENE, A. M., C. E. 

Late Professor of Civil Engineering, University of Michigan 

Author of “Trusses and Arches,” “Structural Mechanics,” etc. 

WILLIAM H. BIRKMIRE, C. E. 

Author of “Planning and Construction of High Office Buildings*” 
“Architectural Iron and Steel, and Its Application in the 
Construction of Buildings;” “Compound Riveted Girders*” 
"Skeleton Construction in Buildings,” etc. 

FRANK W. SKINNER 

Lecturer on Field Engineering, Cornell University 

Author of “Types and Details of Bridge Construction” 

JAMES J. LAWLER 

Author of “Modern Plumbing, Steam and Hot-Water Heating” 

WILLIAM H. BURR, C. E. 

Professor of Civil Engineering, Columbia University, New York 

Author of “Elasticity and Resistance of the Materials of Engineer¬ 
ing;” Joint Author of “The Design and Construction of 
Metallic Bridges” 

HOMER A. REID 

Assistant Engineer, Bureau of Buildings, New York City 

Author of "Concrete and Reinforced Concrete Construction” 

J. B. JOHNSON, C. E. 

. Author of “Materials of Construction ;” “Engineering Contracts and 
Specifications;” Joint Author of “Theory and Practice in the 
Designing of Modern Framed Structures” 


AUTHORITIES ON CONSTRUCTION 


W. E. WAKE 

Formerly Professor of Architecture, Columbia University, New York 
Author of “Shades and Shadows;” “Modern Perspective,” etc. 

JOHN CASSAN WAIT, M. C. E., LL. B. 

Formerly Assistant Professor of Engineering, Harvard University 
Author of “Engineering and Architectural Jurisprudence;” “The 
Law of Contracts,” etc. 

T. M. CLARK 

Author of “Building Superintendence;” “Architect, Builder, and 
Owner before the Law,” etc. 

CLARENCE A. MARTIN 

Director of College of Architecture, Cornell University 
Author of “Details of Building Construction” 

CHARLES H. SNOW 

Dean of School of Applied Science, New York University 
Author of “The Principal Species of Wood, Their Characteristic 
Properties” 

GAETANO LANZA, S. B., C. E. 

Head of Department of Mechanical Engineering and Applied 
Mechanics, Massachusetts Institute of Technology 
Author of “Applied Mechanics” 

A. W. BUEL AND C. S. HILL 

Authors of “Reinforced Concrete” 


NEWTON HARRISON, E. E. 

Author of “Electric Wiring, Diagrams and Switchboards” 

EVERETT U. CROSBY and HENRY A. EISKE 

Authors of “Handbook of Fire Protection for Improved Risk” 

GEORGE E. THACKRAY, C. E. 

Structural Engineer, Cambria Steel Co. 

Author of “Handbook of Information Relating to Structural Steel” 

ALPHA PIERCE JAMISON, M. E. 

Assistant Professor of Mechanical Drawing, Purdue University 
Author of “Elements of Mechanical Drawing ;” “Advanced Mechan¬ 
ical Drawing,” etc. 

RUSSELL STURGIS 

Author of “A Dictionary of Architecture and Building;” “How 
to Judge Architecture,” etc. 

A. D. E. HAMLIN, A. M. 

Professor of the History of Architecture, Columbia University, 
New York 

Author of “A Textbook of the History of Architecture” 

ROLLA C. CARPENTER, M. S., C. E., M. M. E. 

Professor of Experimental Engineering, Cornell University 
Author of “Heating and Ventilating Buildings” 


AUTHORITIES ON CONSTRUCTION 


I. J. COSGROVE 

Author of “Principles and Practice of Plumbing” 

WILLIAM PAUL GERHARD, C. E. 

Author of “A Guide to Sanitary House-Inspection“Sanitation of 
Public Buildings,” etc. 

FRANK 0. DUFOUR, C. E. 

Assistant Professor of Structural Engineering, University of Illi¬ 
nois 

Author of “Bridge Engineering—Itoof Trusses” 

H. H. CAMPBELL 

Author of “Manufacture and Properties of Structural Steel” 

IRA S. GRIFFITH, A. B. 

Supervisor of Manual Training, Oak Park, Ill. 

Author of “Essentials of Woodworking.” 

WILLIAM J. BALDWIN 

Author of “Steam Heating for Buildings” 

CLIFFORD DYER HOLLEY, M. S., Ph. D., anti E. F. LADD, B. S. 

Authors of “Analysis of Mixed Paints, Color Pigments, and Var¬ 
nishes” 

JAMES H. MONCKTON 

Author of “Stair-Building” 

HARMON HOWARD RICE 

Author of “Concrete-Block Manufacture: Processes and Machines” 

H. G. RICHEY 

Superintendent of Construction, U. S. Public Buildings 
Author of “A Handbook for Superintendents of Construction, Archi¬ 
tects, Builders, and Building Inspectors;” “The Building 
Mechanic’s Ready Reference” 

J. A. L. WADDELL, C. E., D. Sc., LL. D. 

Author of “De Pontibus;” “Specifications and Contracts,” etc. 

R. M. STARBUCK 

Author of “Modern Plumbing Illustrated” 

SYDNEY F. WALKER, M. I. E. E. 

Author of “Electric Lighting and Heating” 

ernest McCullough, c. e. 

Author of “The Business of Contracting;” “Reinforced Concrete,’ 
etc. 

GEORGE D. ARMSTRONG 

Author of “Cyclopedia of Painting” 


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DRAFTING TABLE IN THE OFFICE OF A WORKING ARCHITECT. 

Note case for reference books at right, and for current magazines and catalogues at left. 




































Preface 


T HE Building Industry, in its various branches, is more 
closely identified than any other with the marvelous 
engineering progress of the present day and the untold 
possibilities of the future. To put all classes of workers in 
familiar touch with modern methods of construction and the 
latest advances in this great field, and to bring to them in a 
form easily available for practical use the best fruits of the 
highest technical training and achievement, is the service 
which the Cyclopedia oe Construction aims to render. 

The work is pre-eminently a product of practical experi¬ 
ence, designed for practical workers. It is based on the idea 
that even in the larger problems of engineering construction, 
it is not now necessary for the ordinary worker in concrete, 
or steel, or any other form of material, to attempt the 
impracticable task of exploring all the highways and byways 
where the trained engineer or technical expert finds himself 
at home. The theories have been worked out; the tests and 
calculations have been made; observations have been recorded 
in thousands of instances of actual construction; and the 
results thus accumulated form a vast treasure of labor-saving 
information which is now available in the shape of practical 
working rules, tables, instructions, etc., covering every phase 
of every construction problem likely to be met with in 
ordinary experience. This is perhaps most apparent in the 
sections on Cement and Concrete Construction, Plain and 
Reinforced. To this subject, on account of its supreme impor¬ 
tance as a structural factor of the present day, three entire 
volumes are devoted, embodying the cream of all the valuable 
information which engineers have gathered up to date. Much 
of this practical information now presented in this Cyclopedia, 
has never before been published in any form. By its use. 



PREFACE 


anyone is enabled to take advantage of the vast labors of 
others, and to bring to bear on any problem confronting him 
the results of the widest experience and the highest skill. 

The keynote of the Cyclopedia is found in the emphasis 
constantly laid on the practical as distinguished from the 
theoretical form of treatment, in its total avoidance of the 
complicated formulas of higher mathematics, and in its reduc¬ 
tion of all technical subjects to terms of the simplest and 
clearest English. Throughout the pages devoted to Steel 
Construction, for example, the mathematics of the subject 
have been eliminated to such an extent that the reader will 
not find a single instance where even a square root sign has 
been used. 

In addition to the larger problems of engineering and 
building construction, one entire volume, as well as many 
chapters scattered through the work, is devoted to those 
smaller constructions that are of special interest to the 
teacher or student of manual training or the home shop 
worker of a mechanical turn of mind. 

Inasmuch as a wider knowledge and a more intelligent 
grasp of the fundamental principles of construction and 
design will tend to greater efficiency on the part of working¬ 
men, and to greater economy in production, the purpose of 
the Cyclopedia of Construction is one which will appeal 
strongly, not only to the men themselves, but also to the 
architectural and engineering fraternity as a whole. 

The authors of the various sections are all men of wide 
experience whose recognized standing is a guarantee of 
reliability and practical thoroughness. 




Tabl e of Contents 


Mechanical Drafting.Page 1 

The Draftsman’s Outfit—Instruments and Materials—Testing 
Instruments—Use of Instruments—Drawing to Seale—Pencil¬ 
ing and Inking—-Geometrical Constructions—Approximations— 
Projection (Orthographic, Oblique, Isometric, etc.)—Planes of 
Projection—Ground Line—Quadrants—Plans and Elevations— 
Direction of Oblique Lines; Slope—Profile Plane—Auxiliary 
Planes of Projection—Intersection and Development—Noii- 
Developable Figures—Intersection of Planes—Of Plane and 
Curved Surface—Of Plane and Cylinder—Of Solids—Visibility 
of Lines of Intersection—Development of Prism, Pyramid, 
etc.—Intersection of Cylinder and Prism—Of Curved Surfaces 
—Approximate Developments—Problems in Drafting for Con¬ 
struction (Finding Miters, Developing Mouldings, etc.)—Picto¬ 
rial Drawing—Perspective Projection—Isometric Drawing— 
Non-Isometric Lines—Isometrics of Cylinders, Cones, etc.— 
Oblique Projection. 

Working Drawings.Page 145 

Qualifications of the Draftsman—Detail Drawings—Assembly 
Drawings—Preliminary Sketches—Requirements of Good Draw¬ 
ings—Explanatory Notes—Conventional Lines—Shade Lines— 
Blue-Prints—Tracing—Dimensioning—Extension Lines — Over- 
All Dimensions—Finished Surfaces—Sections—Cross-Hatching 
—Conventional Representations of Materials—Lettering of 
Drawings—Spacing—Drawings for Building Construction— 
Working Plans (Basement, First Floor, etc.)—Structural 
Drafting—Solid and Built-Up Members—Rivets and Bolts— 
Reading Drawings. 

Architectural Drafting .... Page 187 

General Requirements—Negotiating with Owner—Scale of 
Drawings—Changes in Plans—Preliminary Sketches—Per¬ 
spective Sketches—Competition Drawings—Working Drawings 
(General and Detail)—Scale and Full-Sized Drawings—The 
Plan—Layout of Rooms, etc.—The Elevation—Use of the 
Orders—Characteristics of Types of Buildings (Residence, 
Library, Schooihouse, Office Building, Warehouse, etc.) — 
Colonial Architecture—General Composition—Treatment of 
Elevations—Location of Openings—Scale Details—The Section 
—Full-Sizing—Reproducing Drawings (Blue-Printing, White- 
Printing, Hectograph Process, etc.)-—Tracing Cloth—Architec¬ 
tural Forms—Conventional Symbols (Drain and Sewer Pipe, 
Lighting, Heating, etc.)—Sizes of Furniture—Materials of 
Construction—Shades and Shadows—Direction of Light— 
Shadows of Points, Lines, etc.—Details of Construction— 
Cornice—Floors—Lath and Plaster—Flashing and Counter- 
Flashing—Doors—Porches—Fireplaces—Stairs—Windows, etc. 

Sketching; Pen and Ink Rendering; Wash 

Drawing.Page 298 

Principles of Sketching—Pencils and Paper—Method—Laying 
Out a Drawing—Rendering (in Pencil, in Ink, in Water-Color) 

—Wash Drawings. 

Orders of Architecture; Architectural 

Lettering.Page 317 

Tuscan, Doric. Ionic, Corinthian, and Composite Orders— 
Entablature, Column, Pedestal—Architrave, Frieze, Cornice— 
Column Details—Units of Measurement—Classic Mouldings— 
Forms and Proportions of Letters—Spacing—Titles and 
Inscriptions—Types of Letters for Various Uses. 

Index.Page 343 










PLATE 1 —Mechanical Drafting. 

















Mechanical Drafting 


INTRODUCTION 

1. Mechanical drafting or drawing is the 
process of representing on paper, by means of 
one or more figures, the shape and size of an 
object, and the relation of its different parts 
one to another. It is the medium of communica¬ 
tion between the designer or architect and the 
mechanic or builder, and, as such, has very great 
practical value. The engineer plans a bridge, 
the architect a building; their ideas are repre¬ 
sented on paper by suitable mechanical draw¬ 
ings of the structures; and these drawings are 
turned over to the contractor or builder to show 
the shape, dimensions, and details required. 

A knowledge of mechanical drafting is indis¬ 
pensable to the engineer, the architect, the 
contractor, the inventor, the carpenter, the 
machinist, and, in short, to everyone whose work 
lies along these or similar lines. 

Mechanical drafting, as the name implies, is 
done chiefly by the use of instruments. Free¬ 
hand drawing, however, is frequently used in 
connection with mechanical, especially in pre¬ 
liminary sketching and in ornamental work. 

1 



2 


MECHANICAL DEAFTING 


THE DRAFTSMAN’S OUTFIT 

2. For a beginner to do good work, reliable 
tools are necessary. It is worth while to pay a 
little more money at the outset in order to have 
an equipment which will give satisfactory 
service. Perhaps nothing is more disheartening 
to a beginner than to have his best efforts meet 
with little success, on account of poor instru¬ 
ments. For mechanical drafting, the articles in 
most common use constituting the draftsman’s 
outfit are the following: 

Set of instruments. 

Drawing board. 

Thumb-tacks. 

T-square. 

Triangles. 

Irregular curves. 

Scales. 

Pricker. 

Erasers. 

Pencils. 

Ink. 

Paper and tracing cloth. 

Sandpaper or fine file. 

Small oil-stone. 


Besides these, there are many others which 
are used at times, especially by the professional 
draftsman—such as the protractor, erasing 
shield, burnisher, proportional dividers, section 
liner, beam compasses, steel straight-edge, 
pantograph, brushes, etc. 

3. The set of drawing instruments is the item 


MECHANICAL DRAFTING 


3 



Fig. 3. Compass. 




Fig. 4. Lengthening Bax. 



Fig. 5. Compass Pen. 




Fig. 8. Bow Pencil or Small Compass. 



Fig. 9. Bow Pen. 



Fig. 10. Ruling Pen. 

(Cuts by courtesy of T. Alteneder & Co.) 

























4 


MECHANICAL DRAFTING 


of greatest cost, and should be selected very 
carefully. A good set purchased from some 
reliable house, will, with proper care, do good 
service for years. These sets are sold in various 
ways—some being put up in a leather case with 
a stiff cover; others, adapted especially for car¬ 
rying in the pocket, being in a case with a limp 
cover and folding flaps. The various pieces may 
also be bought separately, if desired. 

4. Figs. 1 and 2 show a set of instruments in 
two kinds of cases, Fig. 2 being the folding 
pocket style. In Figs. 3 to 10 the different 
instruments are shown separately. 

5. Fig. 3 is the compass. One leg carries 
lead, the other a needle-point. Each leg is 
jointed, and the lower half of one leg is detach¬ 
able at the joint. This is to provide for inserting 
the compass pen or the lengthening bar. 

6. The lengthening bar, Fig. 4, is to enable 
the draftsman to draw pencil or ink circles 
larger than can be drawn with the ordinary 
compass. When the pencil leg is detached from 
the compass, the lengthener is inserted in its 
place, and the pencil leg or the compass pen 
fastened in its end. 

7. The compass pen, Fig. 5, is for inking 
circles or circular arcs, and is inserted in the 
compass in place of the pencil leg. 

8. The hair-spring dividers are shown in 
Fig. 6; and the small dividers or bow spacers in 
Fig. 7. 

9. The bow pencil or small compass and the 


MECHANICAL DRAFTING 


5 


bow pen are shown in Figs. 8 and 9 respectively. 

10. The ruling pen, Fig. 10, is specially de¬ 
signed for ruling straight lines, the ordinary 
writing pen being wholly unsuitable. 

11. The beam compass is shown in Fig. 11. 
This instrument is for accurately laying off dis- 



Fig. 11. Beam Compasses. 


tances, and for drawing circles which are beyond 
the capacity of the ordinary dividers or com¬ 
passes. It consists essentially of the beam (not 
shown in the drawing), a thin straight bar of 
hardwood, and two pieces which slide along the 
bar and which may be clamped to it at any de¬ 
sired distance apart. These sliding attachments 
are called channels, and carry one the needle¬ 
point, and the other the pencil or pen as 














6 MECHANICAL DRAFTING 

desired. As shown at the right, there is a 
micrometer screw for obtaining great precision 
in setting the compass for any given distance or 
radius. 



12. The protractor is shown in Fig. 12. This 
instrument, while not in such constant use as 
some of the others, is nevertheless necessary at 



times. It is made of various substances, such 
as metal, celluloid, cardboard, etc., and is used 
for laying out angles which cannot be obtained 
with the triangles and which cannot be easily 
constructed geometrically. The graduations 









MECHANICAL DRAFTING 


7 


represent degrees or subdivisions; and the 
center of the graduated circle is marked by a 
scratch or small notch on the line through the 
two zero points. A line drawn from the center 
of the circle through any point of division—as, 
for example, through 70—will make an angle of 
70 degrees with the zero line of the protractor. 
Other angles may be drawn in a similar way. 




WORKING 


&_Ol 





Fig. 13. Drawing Board and T-Square. 

13. The drawing board, shown in Fig. 13, is 
used to supply a smooth, even surface on which 
to fasten the drawing paper. It should be made 
of straight-grained, well-seasoned soft wood; 
and the cleats at the ends of the board should 
have straight edges. Some cheap drawing 
boards have a strip of brass or steel screwed on 
at one end; these, however, are likely to warp, 
and are not to be recommended. The board 
should not be allowed to remain in the sun or 
near heating apparatus. 

14. Thumb-tacks are short tacks with large 
flat or almost flat heads, especially used for 
fastening the paper to the drawing board. They 
may be pressed into the soft wood of the board 










8 


MECHANICAL DRAFTING 


with the thumb. Unless the paper is of com¬ 
paratively large size, four tacks—one through 
each corner—will be sufficient to keep the paper 
in place. Small-sized copper tacks may be used 
if preferred, as the heads of these offer less ob¬ 
struction to the motion of the triangles and 
other implements. 

15. The T-square, shown with the drawing 
board in Fig. .13, consists of a blade and a head. 



Fig. 14. Triangles. 


The blade may be permanently fastened to the 
head, or the head may be provided with a clamp 
so as to be adjustable. 

For a right-handed draftsman using the T- 
square against the left-hand side of the board, 
the upper edge of the blade is the working edge, 
as shown in Fig. 13. A good T-square should 
have a perfectly straight working edge, a 
straight working edge also for the head, and no 
motion between head and blade. The most 
accurate T-squares are made of steel, but very 
satisfactory ones are made of wood—some with 










MECHANICAL DRAFTING 9 

plain edges, and others with edges of ebonv or 
celluloid. 

T-squares are made in various sizes, and 
numbered according to the length of the blade in 
inches. When not in use, the T-squares should 




Fig. 15. Irregular or French Curves. 


be hung up, using the hole in the end of the 
blade and should be kept out of the sunlight, 
and away from radiators or steam pipes. 

16. Of the triangles, shown in Fig. 14, 
probably the best for all-round work are those 
made of celluloid, as these are fairly accurate, 
light, and more or less transparent. It is per¬ 
haps hardly necessary to state that celluloid is 







10 MECHANICAL DRAFTING 

highly combustible, and must therefore be kept 
away from fire. 

Triangles are made in different sizes, and 
numbered according to the lengths of the edges. 
A 10-inch 45-degree triangle is one with each of 
the perpendicular edges 10 inches long; a 12-inch 
30-degree 60-degree triangle has the long per¬ 
pendicular edge 12 inches long; and so on for 
other sizes. 

For general work, one should have at least 
four triangles—one large and one small 45- 
degree, 10 or 12 inches, and 5 or 6 inches, re¬ 
spectively; and two 30-degree 60-degree 
triangles—one large and one small. To prevent 
warping, triangles, when not in use, should be 
hung up out of the sun’s rays. 

17. Irregular or French curves of various 
shapes are shown in Fig. 15, and are used for 
drawing-in smoothly curved lines which are not 
arcs of circles. 

18. Scales. First of all, scales are not used 
for ruling lines. All straight lines should be 
drawn either with the T-square or with a 
triangle. Scales are made in different shapes 
and lengths, the most common, perhaps, being 
the 12-inch length triangular or the flat with 
beveled edges. 

Scales are also distinguished as Architect’s 
and Engineer’s scales. On the latter, it will be 
sufficient to say that the inch is divided into 
tenths or multiples of ten, and is used chiefly in 
scientific, machine, and engineering work. 


MECHANICAL DRAFTING 


11 


The Architect’s scale is shown in Fig. 16. 
By reference to the figure, it will he seen that 
the scale is triangular, and therefore has six 
faces for division. On one side of one face the 
scale is marked off into inches and divided in 
the usual way. On the other faces are ten dif¬ 
ferent scales, marked at the ends %, y 2 , %, etc. 



Fig. 16. Architect’s Scale. 


These numbers mean that the scale so marked 
is the scale % inch to the foot, y 2 inch to the 
foot, and so on. 

Let the scale of y 2 inch=l foot be taken as an 
example. By actually examining a scale, the 
draftsman will see that the space at the end 
marked y 2 , which is actually one-half an inch 
in length, is divided into twelve equal parts, so 
that if one-half inch be taken to represent one 
foot, then each smallest space will stand for one 
inch. The other spaces at the right of the 
divided one are half-inches, and so will each 
represent one foot. 

The use of the scale in making actual draw¬ 
ings will be explained later. 

19. The pricker is a fine needle-point fast¬ 
ened in a convenient handle, and is used for 
accurately noting the position of a given point. 

20. Erasers are frequently needed by the 






12 


MECHANICAL DRAFTING 


draftsman for making changes or correcting 
errors in the drawing. They are of two kinds— 
for pencil and for ink. For erasing ink lines, 
a sand-rubber eraser or a steel eraser may be 
used. The steel eraser is a special knife sharp¬ 
ened to a keen edge. With this knife, most of 
the ink may be removed, then the remainder 
rubbed off with the sand or pencil rubber. 

21. Pencils. Special pencils are required for 
drawing, the ordinary kind being as a general 
thing entirely unsuitable. Drawing pencils are 
marked at one end with a number or with one or 
more letters, to show the degree of hardness. 
The hardness of the lead varies from 7 or 8H, 
very hard, to one or more B’s, very soft. 

22. Drawing ink is made in two forms—the 
liquid, ready for use; and the dry, in stick 
form. If the latter is used, it is prepared by 
grinding with a little water in a stone saucer 
until the water containing the dissolving ink is 
perfectly black and of the desired thickness. 
The bottled inks are made in black and in colors. 
Some of these inks are made waterproof, not 
being affected by moisture. For general work, 
the bottled ink is recommended for satisfactory 
results and economy of time. 

23. Paper. The kind of paper varies with 
the sort of work to be done. Drawings from 
which blue-prints are to be taken are commonly 
made on a cheap brown detail or duplex paper, 
or on thin, tough white bond. For nicely fin¬ 
ished drawings, cold-pressed and hot-pressed 


MECHANICAL DRAFTING 


13 


papers are excellent, the latter being especially 
adapted for ink work. 

Another paper which is very satisfactory for 
ink drawing is the normal, which has a hard, 
smooth surface. For the highest grade of inked 
drawings, as for the Patent Office, for book 
work, etc., bristol board is preferred. This is a 
cardboard made of two or more layers; has a 
very hard, smooth surface; and gives very 
sharply defined and clean-cut lines. 

24. Tracing cloth is used when drawings are 
to be reproduced in blue-prints for shop or field 
use. One side of the tracing cloth has a dull 
finish, the other side being shiny. Ink may be 
used on either side of the cloth. Erasers may be 
used as on drawing paper, except that the ink 
eraser or sand rubber should be used very care¬ 
fully so as not to wear a hole through the cloth. 
Water ruins the surface for drawing. 

Testing of Instruments 

25. Testing the T-Square. Place on the 
board a sheet of drawing paper at least as long 
as the blade of the T-square, and, with a sharp, 
hard pencil, draw a line across the paper close 
against the upper or working side of the blade, 
Fig. 17. Then, without changing the position of 
the T-square turn the paper end for end; place 
the line to coincide as nearly as possible with the 
same edge of the T-square; and draw a line 
again. If the second line falls exactly upon the 
first, the edge of the T-square is straight; but if 


14 


MECHANICAL DRAFTING 


the lines do not exactly coincide, the edge is not 
true, and should be made so with a plane or 
sandpaper. 

If the edge of the T-square has been found 
straight, the working edge of the drawing board 
(the edge against which the head of the T-square 
slides), may be tested by applying to it the 
tested edge of the T-square. 

26. Testing the Triangles. A common fault 
with triangles, especially the larger ones, is a 



Fig. 17. Testing the T-Square. Fig. 18. Testing the Triangle. 


lack of accuracy in the right angle; that is, one 
side is not exactly square or at right angles with 
the other side. 

To test for squareness of the right angle'; 
(see Fig. 18), place one side of the triangle 
against the tested edge of the T-square as shown 
at A, and, with a very sharp, hard pencil, draw 
a line against the vertical edge of the triangle. 
Next turn the triangle over, face-down, in the 
position shown at B, and draw against the ver¬ 
tical edge a second line to coincide if possible 
with the first one. If the two exactly coincide, 
the right angle is true. Both the 60-degree 30- 




























MECHANICAL DRAFTING 15 . 

degree and the 45-degree triangles should he 
tested in this way.... 

To test the 45-degree angles, if the 90-degree 
angle is found to be true, draw a 45-degree line 
with one of the short sides against the T-square; 
then turn the triangle over, and place the other 
short side against the T-square. If, in this posi¬ 
tion, a second 45-degree line can be drawn 
exactly coinciding with the first, the angle is 
exactly 45 degrees. 

The 60-degree and 30-degree angles can be 
tested after the right angle has been found cor¬ 
rect, by first drawing a T-square line on the 
paper, then drawing with the triangle against 
the T-square two 60-degree lines so as to form 
a triangle having the T-square line as a base. 
Next test with the dividers the relative lengths 
of the three sides. If they are exactly equal, 
the 60-degree and 30-degree angles are both 
correct.. 

HOW TO USE THE INSTBUMENTS 

27. Drawing Board, T-Square, and Triangles. 

Tack a sheet of drawing paper on the board by 
a thumb-tack at each corner, and let the T- 
square rest on the paper, with the head against 
the left edge of the drawing board. If the 
draftsman is left-handed, he should use the T- 
square against the right edge of the board. If 
now a line be drawn on the paper against the 
blade of the T-square (Pig. 19), then the T- 
square slid along the edge of the board, and 


16 


MECHANICAL DRAFTING 


other lines drawn in the same way, these lines 
will be parallel to one another. 

In making drawings, the drawing board 
should either lie flat on the table or desk, or be 
raised slightly at the back, giving a forward 
inclination. 

The pencil should always be drawn, not 
pushed. 

Only the upper or working edge of the T- 
square is used in drawing. 



Fig. 19. Drawing Parallel Fig. 20. Drawing Angles of 
Lines with T-Square. 15 and 75 Degrees. 


28. For drawing vertical or inclined lines, 

the triangles are used. When one of the shorter 
sides of a triangle is placed against the edge of 
the T-square, a vertical line may be drawn 
against one of the other sides, and a slanting 
line against the third side. This slanting line 
will be at 45 degrees for the 45-degree triangle, 
and at 30 or 60 degrees for the other triangle 
according to the side of the triangle which is 
placed against the T-square. 

Lines making with the edge of the T-square 
angles of 15 degrees or 75 degrees, may be 























MECHANICAL DRAFTING 17 

drawn by combining the 45-degree and the 30- 
degree 60-degree triangles, as shown in Fig. 20. 

Inclined lines which are not at an even angle, 
may be drawn parallel to any desired direction 
as follows: 



Fig. 21. Drawing Parallel Lines in Any Desired Direction. 


In Fig. 21, AB is an inclined line, and other 
lines are to be drawn parallel to AB and above 
it. Place one triangle, as C, with one edge coin¬ 
ciding with line AB ; and place another triangle, 
as D, against another edge of C as shown. Now, 
if triangle 0 slides along triangle D into the 
dotted positions, lines drawn against the upper 
edge of C will be parallel to AB; thus EF and 
GH are parallel to AB. 

29. To Draw Lines Perpendicular to a Given 
Inclined Line. In Fig. 22, AB is the given in¬ 
clined line. Place a triangle, as C, with its long¬ 
est edge coinciding with the line AB; and place 
another triangle, as D, in contact with the lower 
left-hand edge, as shown. Next revolve the tri¬ 
angle C around, as shown by the arrows, into the 







18 


MECHANICAL DRAFTING 


position EFG; then the long edge in the posi¬ 
tion EF is perpendicular to the line AB. Other 
lines perpendicular to AB may be drawn 
by holding triangle D fast, keeping EG against 
the edge of D, and sliding triangle EFG along 
the edge, when lines drawn against the different 
positions of EF will all be perpendicular to AB. 



Fig. 22. Drawing Lines Perpendicular to a Given Inclined Line. 

30. In connection with the T-square, it will 
be well for the beginner to remember the fol¬ 
lowing Don’ts: 

Don’t change T-squares while making a 
drawing. If this must unavoidably be done at 
any time, see first if lines can be drawn with 
the second T-square which shall exactly coincide 
with the first. If not, unless the square has an 






MECHANICAL DRAFTING 19 

adjustable bead, the paper must be taken off 
the board, and then readjusted to agree with 
the second T-square. 

Don’t use the T-square for a thumb-tack 
hammer. 

Don’t use the working edge of the T-square 
as a straight-edge for trimming drawings. 

31. In laying out the border line for a draw¬ 
ing, if the trimmed sheet is to be only a little 
smaller than the size of the paper, the center 
should first be found by means of the diagonals, 
and the border line laid from the center. If, 
however, there is ample paper, the border line 
may be drawn at once without finding the 
center. 

32. Pencils. For line drawing, the pencils 
should be sharpened to a chisel edge, with cor¬ 
ners rounded. It is an excellent idea to have 
the pencil most used sharpened at both ends, 
one with a chisel edge, and the other with a fine 
conical point. The latter point is used for 
making letters, numbers, marking points, etc. 
The compass lead may be sharpened to a chisel 
edge or conical point, although here the chisel 
edge is more satisfactory. 

33. The Architect’s Scale. Often, in actual 
practice, it becomes necessary to make a draw¬ 
ing either larger or smaller than the actual 
object. This is called drawing to scale. If, for 
example, the drawing is to be made one twenty- 
fourth actual size, then each dimension will be 
one twenty-fourth of the real size. To avoid 


20 


MECHANICAL DKAFTING 


the necessity of dividing each dimension by 24 
when making the drawing, the one twenty- 
fourth size scale is used. For one twenty-fourth 
size, one foot would he drawn as one-half inch; 
and one inch as one-twelfth of one-half inch, or 
one twenty-fourth inch. A scale of one twenty- 
fourth size is therefore spoken of as a scale of 
one-half inch to the foot, or, using the signs, 
1/2" = 1 '. 

In Fig. 23 is shown one end of an Architect’s 
triangular scale, in which the upper edge is 
divided to the scale of y 2 " = l'. This would 



Fig. 23. Portion of Architect’s Triangular Scale. 

be used in making a drawing on the scale of 

= 1'. The smallest spaces represent inches, 
and the longer undivided space between 0 and 1 
represents one foot. No mental calculation, 
then, is necessary with this scale, as the required 
dimensions are laid off directly. For example, 
a length of 1 foot 7 inches would be laid off as 
shown in the figure. 

The beginner should become familiar with 
the use of the scale, by actually laying off vari¬ 
ous dimensions in feet and inches, using the 
different scales in turn. 

34. The Compass. Before using the com- 






MECHANICAL DRAFTING 21 

pass (Fig. 3), see that the lead and the needle¬ 
point project the same distance. In drawing 
circles, the compass should be held with the 
thumb and first tw T o fingers at the extreme top, 
with the needle-point pressed on the paper only 
enough to hold it in place. When drawing large 
circles, the legs should be bent at the joints so 
that the lower part of each leg is vertical or 
nearly so. 

35. The Lengthening Bar. The compass 
just described may be used for circles up to 6 
or 7 inches radius; but above this distance, the 
lengthening bar (Fig. 4) should be used, which 
will enable one readily to draw circles up to 9 
inches radius. 

For larger circles, the beam compass (Fig. 
11) should be used. 

To attach the lengthening bar, loosen the 
screw which fastens the pencil leg, remove the 
leg, insert the lengthener, put the pencil leg in 
the other end of the lengthening bar, and tighten 
up both screws. 

36. The Hair-Spring Dividers. The hair¬ 
spring dividers (Fig. 6) are used for laying off 
or transferring exact distances. This some¬ 
times takes the form of dividing a given line, 
straight or curved, into a certain number of 
equal spaces, and it is in this kind of work that 
the hair-spring in the leg is especially useful. 
The screw in the leg is for fine adjustment, for, 
with any setting of the dividers, a slight turn 
of the screw changes the distance between the 


22 


MECHANICAL DRAFTING 


needle-points by a very small amount. Setting 
up the screw increases the space, while turning 
the screw out lessens the distance between the 
points. 

37. The small dividers or bow spacers (Fig. 

7) , are very useful for short distances where 
the large dividers would be awkward to handle. 

38. The bow pencil or small compass (Fig. 

8) is very convenient for circles or arcs of 1 inch 



or less in radius. If a number of small circles 
of the same size are to be drawn, the setting is 
much less likely to be accidentally changed than 
with the large compass. 

39. The bow pen (Fig. 9) is indispensable 
where very small circles are to be inked, and is 
preferable for circles up to 1 inch or 1^4 inches 
radius. 

40. The Irregular or French Curves. Sup¬ 
pose that the points 0, 1, 2, etc., to 10, Fig. 24, 



MECHANICAL DRAFTING 23 

are to be connected with a smooth curve. First 
sketch a freehand curve through the points. 
Next take one of the irregular curves, and find 
a part of the edge which will coincide with the 
sketched curve for as long a distance as possible. 
Beginning at point 0, suppose that the edge can 
be fitted nearly to the point 5, as shown in the 
dotted position A. The curve may then be 
drawn against the edge in this position as far 
as the lengths are exactly coincident. The curve 
is then shifted to another position, as B, so that 
a further portion 5, 6, 7, of the sketched curve 
coincides with a part of the irregular curve, 
and also so that the curve in position B runs 
back and coincides with a part of what is 
already lined in. 

Special attention should be paid to this latter 
statement, for, to insure a smooth, continuous 
curve, it is essential that when each new portion 
of the curve is drawn, the curved edge must 
also coincide with a part of what is already 
drawn. The remainder of the curve through 
points 7, 8, 9, and 10, may be drawn in a similar 
manner, either by the further use of the same 
irregular curve or by the aid of a different one. 

41. Inking. In practical work, drawings 
very often have to be made in ink. This may 
be done in two ways. The pencil drawing may 
be lined in with ink, as in drawings for the 
Patent Office or for book work; or an ink draw¬ 
ing may be made on tracing cloth tacked on the 


24 


MECHANICAL DRAFTING 


board over the pencil drawing. In either case, 
certain general rules apply. 

42. To ink with the ruling pen, place a small 
quantity of ink between the points or nibs of 
the pen, using either a quill or a common writing 
pen. Care should be taken that no ink remains 
on the outside of the ruling pen, otherwise a 
blot is likely to result. In inking straight lines, 
the thumb-screw for regulating the width of 
line is always held away from the straight edge 
which guides the pen. Both nibs should rest 
equally on the paper, and the pen should be 
inclined slightly in the direction of its motion. 
The pen should always be drawn along, never 
pushed. In other words, the pen should always 
follow the hand. 

For right-handed draftsmen, all horizontal 
lines are ruled from left to right; vertical lines 
which are drawn against the left side of the 
triangle are drawn up, and vertical lines ruled 
against the right side of the triangle are drawn 
down. The point of the pen must never quite 
touch the guiding straight edge, and this will 
not happen if the pen is not inclined either 
toward or away from the draftsman. The pen 
should be pressed against the straight-edge with 
only enough force to keep it in place; and no 
great pressure should be made on the paper. 

The pen is to be held by the thumb and the 
first two fingers, and grasped somewhere be¬ 
tween the thumb-screw and the end of the 
handle ? according to the convenience of the 


MECHANICAL DRAFTING 25 

draftsman. To insure a line of even width 
throughout, the pen must have no motion except 
along the paper in the direction of the line being 
drawn. 

An exception to this latter statement must 
be made for inking lines with the irregular 
curve; for then, besides holding the pen nearly 
vertical, it must be turned slightly in the fingers 
when passing around a sharp curve, so that the 
points may remain in the same position relative 
to the curved edge, and the inked line thereby 
retain the same width. 

When inking fine lines, care must be taken 
to clean the pen frequently, as, with a fine line, 
there is a tendency for the ink to cake on the 
end of the pen. It is very convenient when 
inking, to have at hand a small glass of water, 
into which the pen m Q v be dipped when it is 
to be cleaned. 

There are three features of a good ink draw¬ 
ing—first, ink lines which exactly cover the 
original pencil lines; second, lines similar in 
character showing uniformity in width; and 
third, lines smooth and clean-cut in appearance, 
instead of broken and fuzz}^ 

43. To ink with the compass, it is necessary, 
for the best results, to have the legs of the 
instrument bent so that each is perpendicular 
to the paper. When it becomes necessary to 
use the lengthening bar, one hand should grasp 
it lightly near the end so as to steady the pen 
as the circle is drawn. 



26 


EXERCISES IN USE OF T-SQUARE, TRIANGLES, AND SCALES. 











































MECHANICAL DRAFTING 27 

44. To Sharpen the Pen. Unless the pens 
are in good condition, satisfactory work is diffi¬ 
cult or impossible to obtain. Every draftsman 
should be able to keep his pens in good condi¬ 
tion, and with care and practice he will be able 
to do this. After considerable use, the proper 
elliptical shape of the pen points will wear off, 
and the pen will no longer work well. The 
draftsman should then take the oil-stone, and, 
after screwing the points of the pen close 
together, draw it with a rocking motion to and 
fro on the stone, keeping the pen in a plane 
perpendicular to the face of the stone. This 
process—which, of course, still further dulls the 
pen—is to restore the points to the original 
shape. After the proper elliptical shape has 
been produced, the pen should then be held at 
only a slight inclination with the surface of the 
stone, and then rubbed, first on one side and 
then on the other, until the points are suffi¬ 
ciently sharp. Through all the process, the 
points should be kept screwed tightly together. 
No grinding is to be done on the inside of 
the pen. 

PENCILING AND INKING 

Exercises for Practice in Using the T-Square, 
Triangles, and Scales 
PLATE 2 

45. Plate 2 is to be laid out 10 inches by 14 
inches, outside dimensions, with a border line 
9 inches by 13 inches. 


28 MECHANICAL DKAFTING 

The paper used should be a good drawing 
paper, preferably a high-grade hot- or cold- 
pressed paper. The 6H pencil, sharpened with 
a chisel edge, should be used for drawing the 
lines; and a 5H or 6H with round point, for 
marking divisions from the scale. There are 
to be six figures, as shown. 

Figs. A and B are squares, each 3 inches on 
a side, and located on the paper as shown in 
the plate. 

Fig. A is for practice with the T-square and 
triangles on horizontal and vertical lines. In 
this figure, the left-hand and upper sides of the 
square are divided into %-inch equal spaces. 
This is done by placing the scale on the line 
to be divided, taking a sharp, round-pointed 
pencil, and marking off the desired number of 
spaces without moving the scale. 

The lines are then drawn through the points 
of division—one set against the edge of the 
T-square, and the vertical lines against the edge 
of a triangle placed against the working edge 
of the T-square. 

Fig. B is for practice with the 45-degree tri¬ 
angle in two directions. The left-hand and 
lower sides of the square are divided into %-inch 
equal spaces, using the scale as in Fig. A. From 
these points of division, lines are drawn with 
the 45-degree triangle, upward and toward the 
right. After these lines are drawn, another set 
of lines are drawn from the points on the left- 
hand side, and also from the points where the 


MECHANICAL DRAFTING 


29 


first set of lines cut the upper side of the square. 
If the work is accurately done, it will be found 
that the two sets of 45-degree lines cut each 
other at the bottom and right-hand sides exactly 
on the edges of the square. 

In Fig. C, the 30-degree-60-degree triangle 
is the one used. The figure is not an exact 
square, being a little greater in width than 
height; so draw first the left-hand side, making 
it 3 inches long; then draw the top and bottom 
edges a little more than 3 inches, say 3!/g inches. 
The left-hand side of the figure is then divided 
with the scale into 14 -inch spaces; and from 
these points, 30-degree lines are drawn, slanting 
upward and toward the right. Counting down 
from the top, take the point where the seventh 
30-degree line cuts the upper edge; and from 
this point, draw a vertical line downward to 
form the right-hand side of the figure. Next, 
turn the triangle in the other direction; and 
from the points along the top edge, and also 
from the points on the left side, draw 30-degree 
lines, slanting downward and toward the right. 
From the points where these lines cut the bot¬ 
tom edge, the rest of the lines of the first set 
may be drawn. Accurate work will be mani¬ 
fested by a series of intersections falling exactly 
on the right-hand edge of the figure. 

The purpose of Fig. D is to illustrate the 
use of the 30-degree-60-degree triangle, and inci¬ 
dentally to show the construction of the sym¬ 
metrical six-sided figure called the hexagon. 


30 


MECHANICAL DRAFTING 


First draw with the T-square the base line 
1 % inches long, % inch above the lower border, 
and place the left-hand end V /2 inches from the 
left border line. Next draw from the ends of 
this line 60-degree lines as shown, and measure 
very carefully on each the same length as the 
base, 1% inches. Then, from these last-found 
points, draw two other 60-degree lines upward, 
and mark off again the same length. These two 
points should lie at the same distance above 
the base line, and may be joined by drawing a 
line with the T-square, thus forming the top of 
the figure. 

Next draw the diagonal lines of the hexagon, 
connecting the opposite corners. Now divide 
one of these diagonals, as g-h, into six equal 
spaces, using the scale. (This diagonal should 
measure exactly twice the length of one of the 
sides—that is, 3% inches.) 

Drawing from these points of division hori¬ 
zontal lines and 60-degree lines to the next 
diagonals, and connecting the ends, there will 
be constructed two other hexagons like the first, 
but smaller. 

Thus far, if the work is accurate, all of the 
lines are either T-square lines or 60-degree lines. 
Now, with the scale, find the middle point of 
each side of the outside hexagon, and connect 
these points. The lines joining these points 
should be either 30-degree lines or verticals. 
Do the same thing for the two inner hexagons, 


MECHANICAL DRAFTING 31 

testing in the same way the inclined lines to 
see if they are at 30 degrees. 

Fig. E is for an exercise in drawing parallels 
and perpendiculars by means of the triangles, 
without the aid of the T-square. 

First fix the position of the point x, 4 % 
inches from the left border line, and 2 y 2 inches 
above the lower border; and locate point z on 
the same T-square line as the base of Fig. D, 
and 1 inch to the right of X; and join x and z. 
Starting at point z, mark off on line zx, without 
moving the scale, the following distances in 
order: y 2 inch, % inch, % inch, % inch, % inch, 
and y 2 inch. Then draw as a base line a 
T-square line through z, and set off in the same 
way the distances % inch, y 2 inch, *4 inch, 
y 2 inch, y 2 inch, 14 inch, y± inch, y 2 inch, and 
y± inch; and through this last point, draw a line 
parallel to zx, as shown in Fig. 21. This line 
will be the right-hand boundary of the figure; 
and a line drawn through x at right angles to 
line xz, by the method of Fig. 22, will be the 
upper boundary of the figure. Now, by sliding 
one triangle along another, draw lines parallel 
to the upper boundary of the figure from the 
points on line xz, and also from the points on 
the base line. Draw also parallel to xz another 
set of lines from the points on the base line. 

For Fig. F, locate the point c as shown, and 
make the base line cd 1% inches long, making 
the short dashes each about y 8 inch long. Then, 
from c and d, draw 45-degree lines upward, and 


32 


MECHANICAL DRAFTING 


make each one the same length, 1% inches, 
drawing them full lines. Next draw the dotted 
verticals; then the second pair of 45-degree 
lines; then the horizontal at the top of the 
figure. This produces the regular eight-sided 
figure cdefghij, or regular octagon. Draw the 
verticals ch and dg, and the T-square lines fi 
and ej, making them dash lines. The intersec¬ 
tions of these lines give the four corners of a 
square kmoq. 

Next, using the 45-degree triangle, draw eh, 
di, gj, and fc, making the parts solid and dotted 
as shown in the figure. These lines will inter¬ 
sect in the corners of a second square lnpr. 
Now connect the points k, 1, m, etc., forming a 
regular octagon. Finally join 1 with q and 
o, m with r and p, n with k and q, o with r, 
and p with k, thus completing an eight-pointed 
star. 

Inking. The sheet is to be inked—Fig. A, 
with lines of medium thickness; B with heavy 
lines; and C with fine lines; while D, E, and F 
are to he drawn with medium-weight lines. In 
Fig. F the dotted pencil lines are to be erased, 
not appearing at all on the finished ink draw¬ 
ing. Make as nearly as possible the same dif¬ 
ference in weight of line between A and B as 
between B and C. For this first sheet, ink one 
figure at a time. Remember that ink lines must 
not be rubbed with the triangle or T-square 
until they are perfectly dry. 


























■ 


























































FKEEHAND PEKSPECTIVE DEAWING OF A SUMMEK BUNGALOW, 


































































MECHANICAL DRAFTING 33 

GEOMETRICAL PROBLEMS 

46. There are certain problems of geomet¬ 
rical construction which it is essential that the 
intelligent draftsman should know. We shall 
now present some of the more common of these 
problems. 

PROBLEM 1 

To Bisect a Given Straight Line 

Let AB, Fig. 25, be the given line. With B 
as a center, and a radius greater than one-half 



Fig. 25. Bisecting a Given Fig. 26. Bisecting a Given 

Straight Line. Angle. 

the length of the line, describe an arc above 
AB, and another below; and with the same 
radius, and A as a center, draw two other arcs 
above and below AB, cutting the first two arcs 
at the points 1 and 2. A straight line joining 
1 with 2 will divide AB in two equal parts, 
bisecting it at point C. 

NOTE 1—A circular arc would be bisected in the same 
way. 

NOTE 2—The intersecting arcs will cross nearly at 





34 


MECHANICAL DRAFTING 


right angles, and accuracy thereby become easier to 
obtain if the radius used is taken (by eye) between 
two-thirds and three-quarters the length of AB. 

PROBLEM 2 


To Bisect a Given Angle 

In Fig. 26, let AB and BC form the given 
angle at B. With B as center, and any radius, 



Erecting a Perpendicular to a 
Given Line at a Given 
Point in the Line. 


strike an arc cutting AB and BC in points 1 and 
2. With point 1 as center, and any radius 
greater than one-half the distance from 1 to 2, 
strike an arc; and with the point 2 as center, 
and the same radius, draw another arc, cutting 
the one just drawn, in point 3. A line joining 
point B with point 3 is the bisecting line 
required. 

NOTE—To test the exactness of the work, take the 








MECHANICAL DRAFTING 35 

dividers, set one point at 4, open to point 1, then see if 
this span is the same as that from 4 to 2. 

PROBLEM 3 

To Draw a Perpendicular to a Given Line from 
a Given Point Outside 

Let AB, Fig. 27, be the given line, and c the 
given point. With the point c as a center, and 
any sufficiently large radius, describe an arc 
cutting the given line in two points, as 1 and 
2. Then, with 1 as center, and any convenient 
radius, strike an arc (preferably on the other 
side of the line from point c); and with center 
2, and the same radius, strike another arc, inter¬ 
secting the first one in point 3. Connect the 
point 3 with point c, and this will be the per¬ 
pendicular required. 

PROBLEM 4 

To Erect a Perpendicular to a Given Line at a 
Given Point on the Line 

FIRST CASE—When the given point is 
not very near either end of the line. 

Let AB, Fig. 28, represent the given line, 
and c the given point. With c as center, and 
any radius, strike an arc cutting AB in points 
1 and 2; then, with 1 and 2 as centers, and any 
suitable radius, strike arcs intersecting at 3. A 
line drawn from 3 to c will be the desired per¬ 
pendicular. 

SECOND CASE—When the point on the 
given line is at or near one end. 


36 


MECHANICAL DRAFTING 


Let A.B, Fig. 29, be the given line, and c the 
given point. With point c as center, and any 
radius, draw an arc cutting AB at point 1; then, 
with 1 as a center, and the same radius, strike 
an arc cutting the first one at point 2; and with 
2 as center, and the same radius, draw a third 
arc, cutting the first arc again at point 3. Now, 
with 2 and 3 in turn as centers, and any con¬ 
venient radius, strike two arcs intersecting at 
point 4. A line joining 4 and c is the required 
perpendicular. 

PROBLEM 5 

To Draw a Line Parallel to a Given Line and 
at a Definite Distance Away 

In Fig. 30, let AB be the given line, and one 
inch the required distance away for the desired 



Fig. 30. Drawing a Line Para- Fig. 31. Dividing a Straight 
lei to a Given Line at a Line into a Desired Number 

Definite Distance Away. of Equal Parts. 

line. With any two points on the line AB, as 
1 and 2, and the distance one inch as radius, 
describe two arcs, as C and D; and with the 
edge of the triangle, draw a line EF just touch- 
ing or just tangent to these two arcs, and this 
will be the required line. 





MECHANICAL DRAFTING 37 

NOTE—The greater the distance of one line from the 
other, the less accurate is this construction. For a con¬ 
siderable distance between the two lines, an accurate 
construction would be to erect perpendiculars at points 
1 and 2 by the method of Problem 5, mark points on these 
perpendiculars at the required distance from AB, and 
draw the required line through these points. 

PEOBLEM 6 

To Divide a Given Straight Line into Any 
Desired Number of Equal Parts 

Let AB, Fig. 31, be the given line to be 
divided into, say, five equal parts. This con¬ 
struction is, of course, in case the division can¬ 
not be exactly made with the scale. From either 
end of the line, as A, draw a straight line AX 
of indefinite length, at any convenient angle; 
and lay off on AX, beginning at A, any five 
equal spaces, A-l, 1-2, 2-3, 3-4, and 4-5. ' Join 
point 5 with B; and from points 4, 3, 2, and 1, 
draw by means of the triangles (Article 28) 
parallels to 5-B, intersecting AB in points F, 
E, D, and C, and these points will divide AB 
into five equal spaces. 

PROBLEM 7 

To Construct One Angle Equal to Another 

In Fig. 32, let the angle ABC be the given 
one, and let it be required to construct on DE 
as one side an angle equal to ABC. With B 
as center, and any radius, describe an arc cut- 


38 


MECHANICAL DEAFT1NU 


ting AB and BO at points 1 and 2; and with D 
as center, and the same radius, strike a second 
arc P meeting DE at point 3. Then take 2 as 



Tig. 32. Constructing One Angle Equal to Another. 

center, and draw a short arc through point 1; 
and with this radius, and 3 as center, draw a 
short arc intersecting arc 3F at 4. Then a line 
connecting 4 and D will form with the line DE 
an angle equal to ABC. 


PROBLEM 8 


To Draw a Circle through Three Points Not 
in the Same Straight Line 


In Fig. 33, a, b, and c are the given points. 
Connect a with b, and b with c; and then, by 



Pig. 33. Describing a Circle 
through Three Given Points. 


Fig. 34. Inscribing a Circle ir 
a Triangle. 










MECHANICAL DRAFTING 39 


the method of Problem 1, bisect each line. These 
bisectors D and E intersect at a point 1, which 
is equally distant from a, b, and c. Hence this 
point is the center of a circle which will pass 
through the three points. 

NOTE—As three points not in the same straight line 
may always be connected to form a triangle, it follows 
that this construction may be used for drawing a circle 
through the three corners of a triangle, or as it is called, 
circumscribing a circle about a triangle. 


PROBLEM 9 


To Inscribe a Circle in a Given Triangle 


Let ABC, Pig. 34, be the given triangle. By 
the method of Problem 2, bisect any two of the 
angles of the triangle, as the angle at A and 
the one at B; the bisecting lines will intersect 



E—-- p.^ 

36. Constructing a Regular 

Fig. 35. Constructing a Trian- Hexagon of which One 

gle of which Sides are Given. Side is Given. 


each other at point 1. This point is equally 
distant from all three sides of the triangle; 
hence, with 1 as center, the required circle D 
is drawn just tangent to the sides of the tri¬ 
angle, and is the required inscribed circle. 








40 MECHANICAL DKAFTING 

PROBLEM 10 

To Construct a Triangle, Having Given the 
Lengths of the Sides 

In Pig. 35, let AB, CD, and EF be the lengths 
of the sides. Draw line 1-2, and make it equal 
to AB. Then, with point 1 as center, and a 
radius equal to one of the other sides, as CD, 
strike an arc; and with point 2 as center, and 
a radius equal to the remaining side, EF, draw 
another arc, intersecting the first one at point 
3. Join 3 with 1 and 2, and the triangle is com¬ 
pleted. 

PROBLEM 11 

To Construct a Regular Hexagon, Having Given 
One Side 

In Fig. 36, AF is the given side. With points 
A and F as centers, and a radius each time equal 
to length AF, strike arcs intersecting in point 
o; and with o as center, and the same radius, 
draw a circle through A and F. Then, with A 
as center, and the same radius, draw a short arc 
cutting the circle at B; then, with center B, 
radius unchanged, cut the circle again at C; 
repeat this process, beginning with F, obtain¬ 
ing points E and D. Draw AB, BC, CD, DE, 
and EF , and the hexagon is constructed. 

NOTE 1—A polygon of any number of sides which 
has all of its corners in the circumference of an enclosing 
circle, is said to be inscribed in the circle. 

NOTE 2—The length of the radius of a circle may be 
spaced around the circumference exactly six times. 


MECHANICAL DRAFTING 

PROBLEM 12 


41 


To Construct an Ellipse, Having Given Two 
Axes at Right Angles (or the 
Rectangular Axes) 

Let AB and CD, Fig. 37, be the axes, each 
line bisecting the other. The point o will be 
the center of the ellipse. The longer axis AB 
is the major axis; the shorter one CD, the minor 
axis. With center 0, and radius equal to Ao, 
describe an arc cutting AB in points x and y. 
These points are termed the foci of the ellipse. 

The construction to be given depends upon 
the interesting property of the ellipse, that, no 



Fig. 37. Constructing an Ellipse, Having Given the Rectangular 
Axes. 

matter what point on the curve be taken, the 
sum of its distances from the foci is always the 
same, and is equal to the length of the major 
axis. Hence, to find points on the curve, mark 
off on AB, between z and y, any number of 
points, as 1 , 2, 3, 4, etc. Then, with x and y 
as centers, and radius equal to A-l, strike four 
short arcs, two above and two below AB; and 
with the same centers, and radius equal to 1-B, 
describe four other arcs, cutting the first four 
at E, E', F , and F'. Eepeat this process for the 





43 MECHANICAL DBAFTING 

other points marked on AB, taking next A-2 
as length of first radii, and 2-B as that of the 
second, obtaining four more points; and so on 
for the remaining points. The curve should be 
first sketched freehand through the points 
found, then drawn in smoothly with the irregu¬ 
lar curve. 

PROBLEM 13 

To Construct an Ellipse with a Trammel, 
Having Given the Rectangular Axes. 

In Fig. 38, AB and CD are the axes of the 
desired ellipse. The trammel K may be a strip 
of stiff paper or thin cardboard. On one of 
the straight edges of the trammel, mark off the 
length EP equal to Ao; and from E, mark off 



Fig. 38. Constructing an Ellipse with a Trammel. 

EG equal to Co. Now take the trammel, place 
it so that point G will be on the major axis AB, 
and point F on the minor axis CD; then point 
E will be at one point of the required curve, 
and the point may be marked on the paper with 
a sharp-pointed pencil or a fine needle-point. 
Then, by placing the trammel in other positions, 
with G on AB, and F on CD, point E will indi¬ 
cate other points on the required ellipse. 






MECHANICAL DKAFTING 43 

Approximations 

47. Often, in practical work, an approxima¬ 
tion will answer the purpose as well as an exact 
geometrical construction. 

For example, let it be required to find a 
stiaight line equal in length to a given curved 
line. 


In Fig. 39, let AB be the given curved line. 
It is required to find on CD a length equal to 



AB. Taking the dividers, and starting at A, 
lay off any number of 'short, equal spaces A-l, 
1~2, 2-3, etc., up to X. (The distance from the 
point X to B should be less than one of the equal 
spaces.) Then, with the same setting of the 
dividers, begin at C, and lay off the same num¬ 
ber of equal spaces as far as XMeasure in 
the dividers the distance XB, and lay it off from 
X' to B'. Then the length CB' is practically 
equal to AB. The curve, which may or may 
not be the arc of a circle, is said to be rectified 
along CD. 

NOTE—Should the distance XB be too short to take 
accurately with the dividers, the distance 5-B may be 
divided into two spaces, and these laid off from 5'. 



FIG. A. it FIG. C, FIG. D. 



44 


PLATE 3 —Mechanical Drafting. 




















































MECHANICAL DRAFTING 


45 


Again, suppose the circumference of a circle 
is to be divided into perhaps eleven equal parts. 
This is most readily and accurately done by 
trial, using the hair-spring dividers. Assume 
first some radius, lay this around the circum¬ 
ference; and if the setting is not found exact 
the first time, adjust slightly by means of the 
hair-spring screw, space again around the cir¬ 
cumference, and proceed in this way until the 
exact spacing is found. 

Exercises in the Use of the Compass and the 
Irregular Curves 

PLATE 3 

48. Plate 3 is laid out 11 inches by 15 
inches, with a border line 10 inches by 14 inches. 
All of the figures are to be accurately penciled; 
then all are to be inked. Pigs. A and D are for 
practice with the irregular curves; and Pigs. B, 
C, and E for practice with the compass. The 
figures are located as shown on the plate. Por 
Pigs. A and D, the irregular curve should be 
used in accordance with the instructions of 
Article 40. 

Penciling. Fig. A represents one turn each 
of two equal spirals. This particular kind of a 
spiral is called the Spiral of Archimedes. Make 
first the outside circle 3inches in diameter, 
and divide the circumference into any number 
of equal parts, as twelve in the figure; and draw 
the diameters. Divide any radius, as OL, into 
the same number of equal parts. Then, with 0 


46 


MECHANICAL DRAFTING 


as center, and radius 0-1, strike an arc cutting 
the first radius at the left in point a; then, with 
the same center 0, and radii 0-2, 0-3, 0-4, etc., 
to 0 - 11 , strike arcs cutting respectively radii 
ON, OP, OQ, etc., to OX, thus determining the 
various points of the curve, o— b—f—k—12. 
The other spiral, o—n—s—y, is constructed in 
a similar way. 

In Fig. D the diameter of the circle is 31/2 
inches, and the short diameter of the ellipse is 
2% inches. The points on the ellipse may be 
found either by the method of Problem 12, 
above, or by the use of a trammel (Problem 13); 
and then these points are joined with the irregu¬ 
lar curve. 

Fig. B is for practice in drawing lines of 
different kinds with the compass. 

In penciling, make the lines of uniform 
width. The square is 3^ inches on a side. The 
points 0 and O' are the centers for the circles 
and arcs. To locate point 0, bisect the angle 
between the diagonal and the upper side of the 
square, by the line Mx, and point 0 is the inter¬ 
section of this bisector with the other diagonal. 
Point 0' may then be located on the other side 
of the diagonal MN. The circles A and A', tan¬ 
gent to the sides of the square and to the diag¬ 
onal MN, are next drawn. Then, from point 1, 
mark off on the bisector Mx 14 -inch spaces, 
three to the left, and six to the right. With 
center 0 , and radius 0 - 2 , draw the circle next 
inside of A, and, before changing the setting of 


MECHANICAL DRAFTING 47 

the compass, draw the corresponding circle from 
center O'. In this same way, draw all the other 
circles and arcs, using each center 0 and O' 
before changing the setting. Make the circles 
and arcs dotted, dot-and-dash, or full, as shown 
in the figure. 

The so-called dotted lines through points 5 
and 6 are really composed of short dashes a 
little less than i/g inch in length. Care should 
be taken to make these dashes uniform in length. 
Similarly, the short and long dashes of the cir¬ 
cles through 2 and 3 should be drawn with care, 
to insure a pleasing and uniform appearance. 

Fig. C is intended for practice in the accu¬ 
rate use of the large and small compasses, and 
also in the accurate use of the scale. The rect¬ 
angle in which the design appears is laid out 
as accurately as possible 5 inches by iy 2 inches. 
It is then divided into l^-inch squares; and 
on the exactness of the spacing depends largely 
the accuracy of the final result. 

An experienced draftsman could set the scale 
along the side of the rectangle, and mark off 
accurately the l^-inch divisions without mov¬ 
ing the scale. The beginner, however, can obtain 
greater accuracy by using the hair-spring 
dividers. 

First set the dividers or the scale to 1% 
inches, and test the exactness of the setting by 
spacing along the scale several times, noticing 
whether, at the last position, the point of the 
dividers exactly coincides with the proper divi- 


48 


MECHANICAL DRAFTING 


sion of the scale. The dividers with this setting 
should then be used to space off on two adjoin¬ 
ing sides of the rectangle. Through these points 
of division, the lines forming the small squares 
are drawn with the triangle and T-square. The 
centers of the circles and arcs are at the corners 
of the small squares, as shown in the drawing. 
The smallest radius is % inch, and the radii 
increase by *4 inch, so that the largest radius is 
1% inches. For accuracy it is essential that 
all arcs or circles of the same radius be drawn 
with one setting of the compass. 

For the penciling, draw first all the arcs, 
then the straight lines. Of course, in the pencil 
work, it is needless to attempt to stop the arcs 
exactly at the straight lines, as this can be done 
when the drawing is inked. 

In Fig. E, the outside square is 3y 2 inches 
on a side. With the corners of the square as 
centers, draw the arcs A, B, C, and D, and 
through the points of intersection, 1, 2, 3, and 
4, draw with triangle and T-square the smaller 
square. Draw the diagonals of the larger 
square; and with the intersection of the diag¬ 
onals as center, draw the circle through 1, 2, 
3, and 4. 

Next, with the corners of the smaller square 
as centers, draw the arcs 1-4, 4-3, 3-2, and 2-1; 
and lastly, draw the smallest circle as in the 
figure, tangent to these four arcs. 

Inking. The border line should be of the 
same weight as the heavy lines of Fig. B. Make 










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A FINE EXAMPLE OF PEN-AND-INK KENDEKING, 


















































































































. 




















M 















































MECHANICAL DRAFTING 49 

all the full lines on the sheet of medium width, 
except as shown in the drawing for Fig. B; and 
make all construction lines fine, short-dash lines 
like those of Fig. B. In Fig. B, the diagonals 
need not be inked. In Fig. C, do not show the 
construction squares in the finished drawing. 
In Fig. D, show the axes of the ellipse as con¬ 
struction lines. In Fig. E, the diagonals and 
the smaller square should not be inked. 
PROJECTION 

49. The term projection as used in mechan¬ 
ical drafting, may be explained as follows: 

Assume any object, as a cube, and a plane 
above it and parallel to the upper face, as in 




Fig. 40. Illustrating Principles Fig. 41. Illustrating Planes of 
of Projection. Projection. 

Fig. 40. Now, if parallel lines be drawn from 
the corners of the cube, and perpendicular to 
the plane, these perpendiculars will meet the 
plane in the points I, 2, 3, and 4; and lines join- 
ing these points will give the four-sided figure 
1-2-3-4, which is called the projection of the 
cube upon the plane. The projection, then, of 
the cube made in this way, is simply a square 
equal in size to one of the faces of the cube. 















50 


MECHANICAL DRAFTING 


There are various kinds of projection, as 
orthographic or orthogonal, oblique, isometric, 
axonometric, etc.; but the first is of most prac¬ 
tical value, and will receive the principal con¬ 
sideration. Where the simple term “projec¬ 
tion” is used, orthographic will be understood. 

Orthographic Projection 

While projections may be made on any 
planes, those most commonly used are one 
vertical and the other horizontal in position, 
being thus at right angles. The line of inter¬ 
section of the two planes is called the ground 
line, or GL. These planes are known as planes 
of projection or co-ordinate planes, and for 
brevity may be referred to as V and H. The 
position of the planes is as in Fig. 41. 

In this figure, let A represent a square placed 
parallel to the V plane, and with two of its sides 



Fig. 42. Projections of a Square in Third Angle. 

perpendicular to the H plane. Then the pro¬ 
jection on the V plane, a square equal to A, is 
shown at A v , while the projection of A on the 
H plane is merely one line, A h . 












MECHANICAL DBAFTING 51 

It will be seen that four angles are formed 
by the intersection of the two planes. These 
angles, or quadrants, are distinguished as first, 
second, third, and fourth, as indicated by the 
numbers, and are always in this same order. 
For practical purposes, drawings are made as 
if the object were in either the 1st or the 3d 
angle. 

50. Fig. 42 shows a square A in the 3d angle, 
placed parallel to V, and two edges perpendicu¬ 
lar to H. It is projected up to H, giving A ' 1 
for the H projection; and forward to V, giving 
A v as the V projection. 

51. Plans and Elevations. In practical work, 
the term plan is used instead of II projection; 
and an H projection or plan, unless otherwise 
expressly stated, is always a view of the top 
or upper side of any object; hence a plan may 
often be spoken of as a top view. 

Similarly, elevation is the usual term for V 
projection, and means a view of the front side 
of an object, or sometimes a view of the right 
or left side. In actual drawing, the H plane is 
taken as the plane of the paper as it lies on the 
drawing board; and the V plane, as an imag¬ 
inary plane vertical in position and directly in 
front of the draftsman. 

It must be noted that when the plan and the 
elevation of any object are both made on the 
same sheet of paper, one can be neither to the 
right nor left of the other; but one must be 
drawn on the paper vertically over the other. 


52 MECHANICAL DRAFTING 

The drawings of Figs. 40, 41, and 42 are pic¬ 
torial, and not actual projections. 

52. Actual Projections. In Fig. 43, a 
T-square line GL may represent the V plane as 
seen from above; and the whole surface of the 
paper, the H plane. Then any object in the 
first or the fourth angle would be projected on 
II on the near side of GL; and any object in 
either the second or third angle would be pro¬ 
jected on the further side of GL. 

The actual plan and elevation of the square 



Fig. 43. Illustrating Principles Fig. 44. Projections of Cube in 
of Projection. Third Angle. 


shown pictorially in the preceding figure may 
now he made. A straight line A h parallel to 
the Y plane and on the further side of V, will 
be the H projection or plan of the square; and 
the square, in its full size below GL, will repre¬ 
sent the projection on V. 

Suppose that the plan of a cube placed in 
the third angle is to be made; and let the cube 
be placed with the top and bottom level, and 
the side faces perpendicular to V. Then, in 
Fig. 44, the plan will be shown as at A h , equal 





















MECHANICAL DRAFTING 53, 


to one side of the cube; and the distance between 
A h and GL is the distance that the cube is behind 
the vertical plane. 

Next, for the elevation or front view of the 
cube, the paper must be considered as the V 
plane, and the GL as H seen edgewise. Then, 
as the cube is below the H plane, its projection 
on V will be below H as seen edgewise—that 
is, below GL. This elevation of the cube will 
be a square A*, vertically below A\ The cor¬ 
ners of the cube may be numbered, calling the 
four upper corners 1, 2, 3, 4, and the four lower 
ones 5, 6, 7, 8. The two projections A' and A h 
are squares of equal size, which is evidently as 


Elle^v, 

* 

Plan * 


Fig. 45. 



□ O © ® o □ 


Elevations and Plans of Simple Objects—First Angle. 


it should be, since each face of the cube is of 
the same size, and each view is taken at right 
angles with the face. 

53. The Co-ordinate Planes Seen Edgewise. 

The GL sometimes represents H, seen edgewise, 
and sometimes V seen edgewise. When con¬ 
sidering a plan or top view, GL is V seen edge¬ 
wise; but when regarding an elevation, GL is 
H seen edgewise. 

Examples. In Fig. 45, six simple objects 
are shown, all in the first angle. Beading from 

















54 


MECHANICAL DRAFTING 


left to right these are: Square prism; round bar 
or cylinder; the same with a square hole from 
one end to the other; the same cylinder again, 
but with a small block placed on the upper end; 
a circular cone standing on H; and a short joist 
with a tenon on the front end. 

Fig. 46 shows the elevation and plan of a 
common hexagonal nut. The double dotted lines 



Il 

:□[ 

Ij 


A 

H 

S b 

II 

i! 

c 



ll 



1) 

Li 



Elevation 



Fig. 46. Hexagonal Nut. 


of the elevation, and the two inner circles of 
the plan, indicate that the nut is threaded. 

Notice that the thickness or height of the 
nut is shown on the elevation; while the true 
distance between the parallel faces is given only 











MECHANICAL DEAFTING 55 

in the plan. Each side of the nut is shown in 
its real width on the plan; but on the elevation, 
of the three front sides A, B, and C, B alone is 
shown in the full width, A and C appearing 
very much narrower. This illustrates several 
very important principles of projection, which 
may be stated thus: 

54. (a) If any flat surface is parallel to II 
or Y, it will be drawn on that plane in its real 
size and shape; but if a surface is oblique to 
H or V, its projection or view on that plane is 
less than the true size, and does not show the 
exact shape. 

Observe that although the face A, for exam- 
pie, is oblique to the V plane, it does not follow 
that all its dimensions are oblique. The height 
of the face A is not affected by the inclination 
of the surface with the vertical, and hence is 
shown in its true length in the elevation. 

55. (b) If any edge of a solid, or any single 
line, is parallel to either H or V, it will be shown 
on that plane in its true length. 

These principles are still further illustrated 
in Figs. 47, 48, and 49. Fig. 47 shows a square 
prism placed with its length vertical. Notice 
the numbering of the top and bottom. Why 
are some of the faces in elevation shown in their 
true size? Only one dotted edge appears. (A 
dotted edge in any projection is understood to 
mean an edge which is not visible in that view.) 

56. In Fig. 48, a regular hexagonal pyramid 
is given standing on its base, and with its axis 


56 


MECHANICAL DRAFTING 


ab perpendicular to H. This solid has six 
sloping surfaces and one base. Of these seven 
faces, the base alone appears in its true size. 



z 




Fig. 47. Elevation and Plan of Fig. 48. Regular Hexagonal 
Square Prism with Length Pyramid with Axis Per- 

Vertical. pendicular to H. 

Two of the inclined edges, a-1 and a-4, are 
shown in their true lengths in elevation at a v -l T 
and a v -4 v , since the lines in space are parallel to 
the vertical plane. 

57. Fig. 49 is precisely the same object as 
in Fig. 48, but placed in a different position. 










MECHANICAL DRAFTING 57 

In this position, the base is parallel to V, the 
axis, a-b perpendicular to H, and the apex 
away from the draftsman. Note the dotted 
lines in the elevation, the only visible part of 
the solid in elevation being the base. The edges 
a-1 and a-4 are now parallel to the horizontal; 
hence their true lengths are a h -l' 1 and a h -4 h . The 
base 1-2-3-4-5-6 is parallel to V; hence perpen¬ 
dicular to H; and its II projection is the straight 
line 1-2 ... 4 . The base in the preceding figure 
is perpendicular to V, and its V projection is 
the straight line l r -2\ . ,4 V . 

The statement of the principle involved is 
as follows: 

58. If a surface is perpendicular to H or V, 
it will be seen edgewise in that view, hence will 
appear simply as one line. 

59. In these three figures on the prism and 
pyramid, it may readily be seen that it would 
be impracticable to draw first the view showing 
the side faces. For example, in Fig. 47, the 
widths of the surfaces in elevation are not 
known until the plan is drawn. Hence, to draw 
a prism, or pyramid, or other object of a similar 
character, draw the base or the end view first. 

This direction applies with equal force in 
other cases of a more practical nature—for 
example, the slope of a roof Is shown at its 
true angle in an end view. 

60. Direction of Oblique Lines; Slope. A 
line may be parallel to one plane and oblique 


58 


MECHANICAL DRAFTING 


to the other, or it may be oblique to both planes. 
This latter position will be meant when a line 
is referred to simply as an oblique line. The 
term slope refers to the direction of a line 
oblique to one or both of the co-ordinate planes. 
In this treatise the word backward, when 





allel to V. 

applied to the slope of a line, means away from 
the draftsman; and forward means toward the 
draftsman. 









MECHANICAL DRAFTING 


59 


Thus, if a line is said fo slope upward, back¬ 
ward, and to the left, the upper end of the line 
must be away from the draftsman and toward 
his left. In the same manner, a line sloping 
downward, backward, and to the right, has its 
lower end away from the draftsman and toward 
his right. If a line slopes simply forward and 
to the left, for example, then neither end is 
lower than the other, and the line is in a hori¬ 
zontal position, with its left-hand end toward 
the draftsman. 

As illustrations of slope of lines, a-1 in Fig. 
48 slopes downward and toward the left; a-4, 
downward and toward the right; a-2, down¬ 
ward, backward, and toward the left; a-6, down¬ 
ward, forward, and toward the left; a-3, 
downward, backward, and toward the right; 
and a-5, downward, forward, and to the right. 

61. Projection of Oblique Lines. A right 
circular cone is shown in Fig. 50. The vertex 
is a; and a-b, a-c, a-d, a-e, and a-k are various 
elements of the cone. On reflection, it will be 
seen that all of these lines have the same actual 
length in space. These lines are also all equally 
inclined to the horizontal plane, and therefore 
the H projections are all of the same length. 
Next, referring to the elevation, a v -b v shows the 
actual length of a-b; a v -c v , a v -d v , and a v -e v show 
gradually decreasing lengths, a v -e v being the 
shortest of all. 

This difference in length corresponds to the 
fact shown in the plan, that a-e makes the 


60 


MECHANICAL DRAFTING 


greatest angle with the Y plane. That is, the 
greater the angle that a line makes with a plane 
of projection, the less will be the length of its 
projection on that plane. 

Observe also that a h -c h and a h -k h make the 
same angle with V; therefore the lines in space 
must make equal angles with V; and their V 
projections, being coincident, are of the same 
length. Hence lines of equal length which have 
the same inclination with V, are projected on 
V in equal lengths. 

From the above, it follows that, for a line 
of definite length, the length of its projection 
on any plane is determined wholly by the angle 
the line makes with the plane. If the line makes 
the greatest possible angle with the plane (90 
degrees), then the projection on the plane has 
no length, but is simply a point. 

62. Eevolution of a Figure around Some 
Line as an Axis. In Fig. 51, consider first the 
rectangle abed, placed horizontally, and having 
its long edges perpendicular to V. Then a h b h c h d h 
is the true size and shape of the figure. The 
rectangle is perpendicular to V, and therefore 
(Article 58) is shown on V as a single line a v c v . 
Now let the rectangle revolve up like a trap 
door, on a h b h as an axis. Then points d and e 
will revolve in arcs of circles having points a 
and b respectively as centers. These circles 
will be perpendicular to the axis ab, and 
hence parallel to V, so that a circle drawn 
on Y, with center at a v , and with radius 


MECHANICAL DRAFTING 


61 


a v -c v , will be the projection of the circles de¬ 
scribed by points c and d in space. 

As the rectangle turns about axis a-b, it 
remains always perpendicular to V, and its pro¬ 
jection on Y will remain a straight line. Then, 
when the rectangle has swung up through 45 
degrees, for instance, its V projection will be 
a line a v b v c v 2 d v 2 , making 45 degrees with the 



Fig. 61. Fig. 52. 

Illustrating Revolution of a Rectangle around an Axis. 


horizontal; and its plan or H projection, show¬ 
ing less than the real width, will be a b b b c h 2 d h 2 . 

The other oblique positions are found in the 
same way—the elevation first, then the plan. 
Finally, when the rectangle is revolved through 

















62 


MECHANICAL DRAFTING 


90 degrees into a vertical position, the H pro¬ 
jection becomes merely the one line a h b h c\d\. 

In Fig. 52, the rectangle abed is placed in 
a vertical position and parallel to V. It is then 
revolved like a door on its hinges about a-b as 
an axis, the successive positions appearing in 
plan at a h b h c h !d h i, a h b h c h 2 d h 2 , etc., until the sup¬ 
posed door is wide open in the position a h b h c h 4 d h 4 . 
The corresponding elevations a v b v c v id v i, etc., are 



then constructed by projecting directly from 
the plan. 

63. Suppose that it is required to draw a tri¬ 
angular prism standing on one end, and with 
one edge of the base at right angles with the 
V plane, Fig. 53. According to the preceding 
directions, the base is drawn first, placed in a 









MECHANICAL DRAFTING 63 

horizontal position, and with the right-hand side 
perpendicular to V. The elevation may then 
be drawn as before explained. 

Now let the object be revolved around the 
edge e-f of the base as an axis. In revolving 
in this way, it is evident that every point of 
the prism will move, except the edge e-f, which 
is the axis. A little thought will show that each 
corner that moves will move in a circle. For 
example, the corner d of the base will revolve 
in the arc of a circle the center of which is at 
point g, the radius of the circle being therefore 
d-g. The line d-g is perpendicular to e-f, and 
must so remain as it revolves. This means that 
the line d-g, parallel to the Y plane at first, will 
remain parallel; and the circle described by 
point d in space will be parallel to Y, and will be 
projected on V in its true size. The arc d v j v k v 
then represents the circle described by the 
motion of point d; and on H, this circle appears 
as the straight line d h j L k h , parallel to V. 

In the same way, the other corners, a, b, and 
c, will each travel in a circle parallel to Y. Then, 
if the prism be revolved through an angle of 45 
degrees, each line of the elevation will simply 
revolve through this angle, with no change in 
length; and the resulting V projection will be 
the rectangle f v d\&\b\, exactly the same size 
and shape as a v b v f v d v , but inclined at 45 degrees 
with the horizontal. This rectangle will be the 
new Y projection of the prism; and, remember¬ 
ing that each point in revolving moves in a circle 


64 


MECHANICAL DRAFTING 


parallel to V, the new H projection may be 
found by dropping perpendiculars from d v 1? ah, 
and bh-ch, to meet parallels drawn from 
d h , a h , b h , and c h , thus determining the points 
d\, a\, b h i, and c\. These points, when joined 
in the proper order, give the new plan as shown 
by the dash lines in the figure. 

64. The principles of such revolution may be 
explained as follows: 

(a) If any object, no matter how complex, be revolved 
about an axis perpendicular to V, the V projection will 
remain unchanged in shape and size, but will revolve to 
different positions with respect to the horizontal. 

(b) The H projection, on the other hand, changing 
shape and size, will be found directly below (or above) 
the new V projection, and each point will be at the same 
distance from V as before revolving. 

A similar statement will apply with merely 
an interchange of V for H, and H for Y, in case 
an object be revolved about a vertical axis. 

Pig. 54 shows the same prism as in Pig. 53; 
but in this figure, the new position has been 
moved a little to the right so as to clear the first 
position. Placing in this way takes more space, 
but is clearer, and should always be used if the 
figure to be revolved is complicated. Notice 
that in the plan of the second position, the upper 
end and the two upper sides are visible, while 
the lower end and the under side are invisible. 

65. Third Plane of Projection or Profile 
Plane. Many times, the two views of an object 
as plan and elevation, are sufficient to describe 


MECHANICAL DRAFTING 


65 


the object completely; but in other cases a third 
view is required to give a satisfactory idea of the 
object in question. Sometimes, in addition, a 
sectional view may be necessary to show fully 
every detail. 


The third view usually taken is in a direction 
perpendicular to that of the plan and the eleva- 



Fig. 54. Drawing Triangular Prism of Fig. 53 in Another 
Position. 


tion. That is, for a rectangular object—as a 
cube or a square prism—there may be the top 
view or plan; the front view or elevation, and 
the third, a profile view or end view. The direc¬ 
tion of the profile view in comparison with the 












66 


MECHANICAL DRAFTING 


other two, is shown in Mg. 55, in which are rep¬ 
resented the plan, elevation, and end or profile 
view of the outlines of a cabin. The end view is 
taken looking in the direction of the arrow. 

It should be noted that the breadth of the 
end view is the same as that of the plan, while 
the height is equal to that of the elevation. 


A 


Ptkcr let oa 
■ hi D VIIW 

Fig. 55. Showing Direction of Profile View as Compared 
with Plan and Ele ration. 

On comparing the three projections, it will 
be seen that the length is shown in plan and 
elevation, the width in plan and profile, the 
height in elevation and profile, and the slope of 
the roof in profile only. In making the three 
views, the profile or end view, in accordance 
with Article 59, should be drawn first. 

66. Third-Angle Projection. Three views of 
a rectangular block, with parts of the top and 
bottom cut away, are shown in Fig. 56. In this 
figure, as in the preceding one, the arrangement 
customary in many drafting offices has been 
followed—of placing the plan above, the eleva- 













MECHANICAL DRAFTING 


67 


tion beneath, and the end or profile view at one 
side. Where this custom is adopted, the view of 
the right-hand end is placed either at the right 
of the elevation, or of the plan; a view of the 
left-hand end is placed at the left; and so on. 
This is known as third-angle projection. Thus, 
in the figure, the end view is a view of the right- 
hand end of the block. 

This figure is an example of a case where the 
plan and elevation do not make the meaning of 
the drawing sufficiently clear and do not make 


PL AM 



Fig. 56. Plan, Elevation, and End View of Bectangular Block 
with Parts of Top and Bottom Cut Away. 

the shape of the object apparent; hence the end 
view is required. The end view bears the letters 
A p , B p , etc. The small p at the upper right-hand 

























68 


MECHANICAL DRAFTING 


of the letter stands for profile, in the same way 
that a small v on the elevation means vertical, 
and a small h in plan means horizontal. 

The end view gives at once a much clearer 
idea of the object than either plan or elevation. 
What is marked A v on the elevation, and A b on 
the plan, in the profile view at A p is shown to be 
a slot. By reference to A h , it will be seen that 
the slot does not extend the entire length of the 
block, and is rounded at the end. The vertical 
dotted line e v -f v represents the left-hand end of 
the slot A. In comparison with A, B p repre¬ 
sents a narrower slot of less depth, and one 
which extends the whole length of the piece. 
This latter statement accounts for the fact that 
B p is left open at the top, while A p is closed. 
The part lettered C h and C v is found on the pro¬ 
file view to be a rounded projection appearing 
at C p . 

Assuming, for the sake of illustration, that 
the plan and elevation are drawn, and that the 
end view is to be constructed from them, it 
would be done as follows: Draw first a center 
line G-H on the plan; then, at any convenient 
distance to the right of the elevation, draw a 
vertical line J-K for the center line of the end 
view. Since vertical heights will correspond on 
the end view with those of the elevation, a T- 
square line through lower edge of D will give 
the level of base of the required view; and a 
second T-square line through the lower edge of 
C v will locate the flat part of the top of the block. 


MECHANICAL DRAFTING 


69 


Next, the width of the end view must be the 
same as that of the plan; hence the distance 
from the center line G-H to point 1 is taken, and 
laid off on the end view from J-K along the line 
L-M to the left, giving point 1; and point 8 is 
located in the same way to the right of J-K. 
Vertical lines drawn through 1 and 8 will give 
the general outline of the end view. Then, 
measuring for the remaining points, and laying 
off from the center line each time, points 2, 3, 4, 
5, etc. are located, those on the near side of G-H 
being measured to the left of J-K, and those on 
the further side to the right. 

Next the depths of the slots as shown on the 
elevation are projected over with the T-square 
to the end view, and A p and B" completed. 
Having located on the end view point 6 as a 
center, the half-circle 0” is drawn with the 
radius 6-7, taken from the plan. The upper edge 
of the shallow groove D T is projected across to 
J-K, becoming the highest point of the curve. 
The radius of the curve being given, its center 
is found on J-K, and the curve drawn-in as the 
arc of a circle, thus completing the end view. 

67. Let it be required to draw a wooden chest 
of given length, breadth, and depth, and to show 
the cover opened through 150 degrees. Evi¬ 
dently this is a case which requires the end 
view to be drawn first. This end view is first 
drawn from the given dimensions at A, Fig. 57, 
showing the cover opened at the given angle. 
The ends of the chest are supposed to be nailed 


70 


MECHANICAL DRAFTING 


to the bottom and sides, which are represented 
in view A by the dotted lines. 

The front elevation, B, is taken looking at A 
in the direction of the arrow. This elevation 
will show the length and height of the chest, 
and will show the cover in its real length, but 
narrower than its true width. The different 
heights are projected over with the T-square 
from A to B. In a view of A in the direction of 




Fig. 57. Profile and Projections of Chest with Cover Open. 

the arrows, 1-2, the extreme left-hand edge of 
the cover, will not be seen; hence this is drawn 
with the dotted line 1-2 in view B. The plan, C, 
shows the length and width of the chest, the 
extreme width of the chest and cover together 
being equal to the distance e-f of the end view A. 























MECHANICAL DRAFTING 


71 


In this view also, the cover appears in less 
than its real width. Note carefully that the 
cover 1-2-3-4-5-6-7-8 is shown less in width in 
elevation than in plan. This is simply because 
the cover is more nearly horizontal than ver¬ 
tical; hence, in looking from above, the cover 
appears more nearly flat-wise, and therefore 
nearly in its real width; while, viewed from the 
front, the cover is seen more nearly edgewise, 
and thus shows narrower. 

This affords an exercise in reading a drawing 
—that is, in obtaining from the various views an 
exact understanding of the different parts of the 
object represented, and also of the object as a 
whole. This figure, and also Figs. 51 to 55, 
illustrate an important principle. 

68. This principle may be stated as follows: 

The size of the projection of any given surface on a 
plane is determined by the angle which the surface makes 
with the plane of projection. If the surface is actually 
parallel to the plane of the drawing, then it will appear 
in its true size; if the surface is perpendicular to the 
plane, it will be seen edgewise simply as a line. 

69. Suppose that a square prism is to be 
drawn standing on one corner, and in an oblique 
position so that its long edges are inclined at 
30 degrees with the horizontal, and that the 
prism inclines upward to the right and away 
from the draftsman. To draw the object in this 
oblique position, in which none of the faces and 
none of the edges will be parallel to either plane, 



72 


Fig. 58. Drawing a Prism in an Oblique Position. 




























MECHANICAL DRAFTING 


73 


requires first the construction of two simpler 
positions. 

The prism is first placed with its base on H, 
and its faces at any convenient angle with V, as 
60 degrees and 30 degrees. This position is 
shown at A, Fig. 58. Next, let the prism be re¬ 
volved about an axis perpendicular to V through 
the right-hand corner of the base. This axis is 
lettered l h -e h on the drawing. The prism is 
revolved until its axis or its long edges make 
30 degrees with H. 

In this kind of a revolution, the Y projection 
does not change shape or size, and will make 
with the ground-line the same angle that the 
prism makes w T ith II (Article 64). Hence the 
elevation can be transferred from A to the 30- 
degree position at B, with point 1 on H. 

The plan may then be constructed as in 
Article 63, Fig. 53, each point of the plan falling 
vertically below its corresponding elevation, and 
in a T-square line to the right of the same point 
in the plan of A. The edges of the prism now 
make the required angle of 30 degrees with the 
horizontal, and one corner is on H; but the final 
inclination has yet to be given. 

In order that the prism shall have the in¬ 
clination specified, it must be turned from the 
position of B so that the upper end will be away 
from the draftsman, and the lower end toward 
him. This may be done by considering the 
prism to revolve about a vertical axis through 
point 1. Each point of the prism will then move 


U MECHANICAL DRAFTING 

in a horizontal circle through whatever angle is 
desired. In this case, let the prism revolve 
about the vertical axis through 60 degrees; then 
point d h will move to d h , in the arc of a circle, 
and l h -d b will be the new H projection of the 
edge 1-d. 

In the same way, every other edge will re¬ 
volve through an angle of 60 degrees, and will 
have its length unchanged. The new or revolved 
plan will therefore be of the same shape and 
size as before this second revolution. For the 
sake of clearness, this revolution is not made 
upon Fig. B; but, instead, the plan is drawn in 
Fig. 0 as it would appear after the revolution. 
The lowest corner 1 may be taken in any con¬ 
venient position, and l h -d h i is drawn at once at 
60 degrees equal in length to l h -d h of Fig. B. 

The plan of C is constructed equal to that of 
B by a method of rectangular co-ordinates, or 
offsets. In the plan of B, perpendiculars are 
drawn from each corner to the front edge 4-k. 
These perpendiculars intersect the edge, or the 
edge produced, in points such as f, g, m, etc. 
Then, through d\, Fig. C, a perpendicular is 
drawn to l-d\, and d\-f is made equal to d h -f; 
and through f, a 60-degree line will represent 
the position of the edge 4 b -k. The distance f-k 
of B, laid off from f of 0, will give corner k in 
Fig. C. Then in C, lay off from f the distances 
f-g, f-m, f-n, etc.; and at these points, erect per¬ 
pendiculars to 4 h -k (these perpendiculars are 30- 
degree lines), and make these perpendiculars 


MECHANICAL DRAFTING 


75 


equal respectively to those of B. In this way 
the remaining corners of the prism are located, 
and the plan completed. 

The elevation may now be constructed from 
the plan, if it is remembered that in the revolu¬ 
tion around a vertical axis the heights of points 
remain unchanged. Hence, if the corners in the 
plan are projected vertically up and to the same 
heights as in the elevation of B, the desired 
points of the elevation will be determined. 
Notice which end of the prism is visible in plan, 
and which in elevation. In following out the 
figure as drawn, care should be taken to imagine 
the shape and position of the object in space as 
described by its projections. 

70. The projections of a cylinder or cone 
may be drawn in any oblique position by a 
process similar to the one just considered. 

Let it be required to construct the plan and 
elevation of a right circular cylinder in the first 
angle, placed with its axis at an angle of 45 de¬ 
grees with the vertical plane, its V projection 
inclined at 30 degrees with H; and let the 
cylinder slope downward, forward, and to the 
right. First, note with which co-ordinate plane 
the axis is to make the given angle. In this case, 
the given angle is 45 degrees with V. Then 
draw the cylinder in the first position perpen¬ 
dicular to V, as in A, Fig. 59. Divide the base 
into any number of equal parts, as in the figure, 
and project these points to the plan. 

Now, if a vertical axis, as X, be taken 



76 


Fig. 59. Drawing Projections of a Right Circular Cylinder in Oblique Position. 














MECHANICAL DRAFTING 


77 


through any convenient point, as 5 on the back 
end, the cylinder may be revolved until it makes 
the required angle of 45 degrees with V. In this 
revolution, the cylinder will remain parallel to 
H, and its plan will be unchanged in size and 
shape; hence, in B, the plan of A is placed at 
45 degrees with Y, sloping forward and to the 
right. 

Since, in the revolution about the vertical 
axis X, each point has moved in a horizontal 
plane, it follows that the heights of points above 
the H plane have not been altered. Therefore, 
from the points of division on the ends of the 
cylinder in the plan, project for the elevation 
to the same level as the corresponding points in 
elevation A. 

The construction is shown for the points 3 
and 7 on one end, and for d and e on the other. 
This construction will give a series of points on 
each end of the cylinder. These points should 
be joined by the use of the irregular curve, pro¬ 
ducing the two ellipses in the elevation. 

For the last position, C, the cylinder must 
be revolved from the position of B without 
changing the angle of 45 degrees with V, until 
the final oblique position is reached. As the 
angle with Y must not be changed, this second 
revolution must be made about an axis perpen¬ 
dicular to V. The axis Y may be imagined to 
pass through any convenient point, as the ex¬ 
treme left-hand point of Fig. B. In this revo¬ 
lution (Article 64), the elevation does not 


78 MECHANICAL DRAFTING 

change shape or size, but simply its position. 
Hence, in Fig. C, the elevation of B is drawn at 
the specified angle of 30 degrees with H, points 
3 2 , 7 2 , d 2 , and e 2 corresponding to the points 3 1; 
7i, di, and ej of Fig. B. 

The plan may now be obtained by project¬ 
ing to meet T-square lines from the plan of B. 



Pig. 60. Drawing Plan and Elevation of Triangular Prism. 


71. Auxiliary Planes of Projection. It has 

been shown in previous figures that often an end 
view must be made before constructing other 








MECHANICAL DRAFTING 


79 


views. Many times this end view may be made 
on H or V. Sometimes, however, it may be 
necessary or convenient to take an end view in 
a direction at right angles with neither V nor H. 

72. Let it be required to draw the plan and 
elevation of a triangular prism as represented 
in Fig. 60. 

Let the ends of the prism be equilateral 
triangles 5 inches on a side. The axis of the 
prism is to be 11 inches long, inclined at 30 de¬ 
grees with Y, backward and toward the right; 
the lowest edge of the prism is to be on H; and 
one face is to make 45 degrees with H. In this 
position, it is evident that a top view will not 
show the end at all, and a view taken in the 
usual direction for elevations will show the end, 
but not in its true size. If, however, a view be 
taken in the direction of the arrow—that is, 
parallel to the direction of the axis—this view 
will be at right angles to the end of the prism, 
and the end will show in its real size and posi¬ 
tion. To take a view in this direction is 
equivalent to projecting the prism on a new Y 
plane parallel to the end of the prism, or—which 
is the same thing—perpendicular to the axis. 

Hence, to make the construction, draw a line 
as Gi-Li in any convenient position perpendicu¬ 
lar to the direction of the axis. This may be 
considered to represent the H plane seen edge¬ 
wise when looking in the direction of the arrow. 
Then, with any point on H for the lowest corner, 
as 1', the end view of the prism is drawn showing 


80 MECHANICAL DRAFTING 

the true size and slope, and one under face at 
45 degrees with H. The width of the face 1-3-4-5 
will appear in plan equal to the distance a-1'; 
and the width of face 1-2-6-5 equal to distance 
l'-b, while the width of the upper face 2-S-4-6 
will equal the length a-b. 

With these widths and the given length of 
the prism, the plan might now be constructed 
without any further reference to the end view. 
It is, however, more convenient and more drafts¬ 
man-like, to draw at any convenient distance 
from Gill!, and parallel to it, a line 4-6 as one 
end; to project at right angles to GJjj, a to 4, 5' 
to 5, and b to 6; then to draw from these points 
the edges 11 inches long and at right angles to 
the end 4-5-6, and finally draw the other end 
3-1-2. 

For the elevation, 1-5 is drawn on the H 
plane as the lowest edge, and directly above 1-5 
in the plan. The height of 3-4 above H is seen 
in the end view as 3'-a, and the height of 2-6 as 
2'-b; hence, in elevation, these edges will appear 
at these respective heights above the plane of 
1-5. The distance 3-c is therefore made equal 
to 3'-a, and 2-d equal to 2'-b. In this elevation, 
the end 1-2-3, nearer the draftsman, is visible. 

73. Summary of Important Principles. The 
important principles above brought out, may be 
summarized as follows: 

(a) An elevation always shows differences in height 
(if any difference in height exists) between different 


MECHANICAL DRAFTING 


61 


objects, or differences in height between different parts 
of the same object. 

(b) A plan or top view means the same thing no 
matter whether the drawing is in the first or third angle; 
similarly, an elevation or front view is the same figure 
for either first or third angle. 

(c) For any given object, upper edges or surfaces are 
visible in plan, and edges or faces on the front are visible 
in elevation. 

(d) A line perpendicular to a plane of projection 
appears on that plane simply as a point. 

(e) A line is shown in its true length in any view, 
only when the line is parallel to the plane on which the 
view is drawn. 

(f) A plane surface is shown in its true size, only 
when it is parallel to a plane of projection. 

(g) A surface perpendicular to a plane of projection 
is seen edgewise on that plane, and appears as a single 
line. 

(h) When one line is revolved about another line as 
axis, each point in the first line moves in a circle whose 
center is on the axis, and the plane of the circle is per¬ 
pendicular to the axis. 

(i) The length of a given line, or the size of a given 
surface, as seen in projection, is determined wholly by 
the angle which the line or surface makes with the plane 
of projection; the greater the angle made with the plane, 
the less the size of the projection. 

74. It will be found that the exercises given 
below will, if worked out, afford helpful practice 
in applying the principles of projection. 

Exercises in Projection 

Exercise 1 —Place in First Angle. Draw the 
plan and elevation of a square prism, with its 


82 


MECHANICAL DRAFTING 


edges vertical, and with two of its faces at 30 
degrees with the vertical plane. The base of 
the prism is 2 inches square, and the length is 
4 inches. Show a circular hole 1 inch in diam¬ 
eter bored through from one end to the other. 

NOTE—Two positions are possible, for the face at 
30 degrees with V may be inclined either to the left or 
to the right. 

Exercise 2 —Third Angle. Draw the plan 
and elevation of a prism of the same shape and 
size as in Exercise 1; but place the prism per¬ 
pendicular to Y, and make two faces incline at 
60 degrees with H. Show the hole in the prism 
as before. 

Exercise 3 —Third Angle. Draw the plan 
and elevation of a right circular cone with the 
base horizontal and the vertex down. The base 
is 3 inches in diameter, and the altitude is 4 
inches. Locate the base y 2 inch below the H 
plane, and the center of the base 1% inches 
from V. 

Exercise 4 —First Angle. Draw the plan 
and elevation of a regular hexagonal pyramid 
standing on its base. Make the left-hand front 
edge of the base at an angle of 45 degrees with 
V. Each side of the base is to be iy 2 inches 
long, and the altitude of the pyramid is to be 
4 inches. 

Exercise 5 —First Angle. Draw the plan and 
elevation of a rectangle placed parallel to V, 
with its long sides perpendicular to H. Make 


MECHANICAL DRAFTING 83 

the rectangle 4 inches by 2y 2 inches. Cut off 
the upper right comer by a 45-degree line drawn 
through the middle of the top side. Now revolve 
the rectangle forward about its left-hand side as 
an axis, through 180 degrees, and show the 
respective projections at the 30, 60, 90,120,150, 
and 180-degree positions. 

Exercise 6 —Third Angle. Draw the plan 
and the elevation of a pile of three blocks placed 
as follows: each one of the three blocks lies on 
its widest face; all of the blocks have their cor¬ 
responding edges parallel; the lowest block is 
on the H plane; the next higher one is placed 
in the center of the top of the lowest one; and 
the top block is in the center of the second. All 
three blocks are rectangular, and all have their 
long edges inclined at 60 degrees with V, back¬ 
ward and toward the left. The bottom block 
is 5 inches by 2% inches by % inch; the middle 
one is 4 inches by 2 y 2 inches by y 2 inch; and the 
top one is 3 inches by 2 y 2 inches by % inch. 

Exercise 7 —Construct a profile view of the 
blocks in Exercise 6, looking from the right. 

Exercise 8 —First Angle. Construct the 
plan and elevation of a rectangular prism 4 
inches by 2 inches by iy 2 inches. The long 
edges are parallel to both H and V. Place the 
prism so that the lower back face makes 30 de¬ 
grees with H. 

Suggestion—The end or profile view must 
be drawn first. 


84 


MECHANICAL DRAFTING 


NOTE—Two solutions are possible, since the lower 
back face may be taken either as the wide or the nar¬ 
row one. 

Exercise 9 —Third Angle. Draw the plan 
and elevation of a right triangular pyramid, 
placed with its axis parallel to both V and H, 
with the apex at the left of the base. Locate the 
axis of the pyramid 3 inches from H, and 2% 
inches from V. The axis is to be 4 inches long, 
and the base is to be an equilateral triangle 2 
inches on a side. Let the lower front edge of the 
base incline at 45 degrees with the horizontal 
plane. 

Exercise 10 —First Angle. Draw the plan 
and elevation of a regular hexagonal pyramid, 
with its axis parallel to both V and H, and with 
its apex at the right of the base. Place the 
lowest corner of the base on the H plane, and 
make the lowest front edge of the base at an 
angle of 15 degrees with H. The axis of the 
pyramid is 5 inches long, and each edge of the 
base is iy 2 inches. 

Exercise 11 —First Angle. Draw the plan 
and elevation of a rectangular prism 5 inches by 
2 inches by 1% inches, when the long edges are 
horizontal and are placed at an angle of 45 de~ 
grees with Y, backward and to the left. Make 
the lower front face one of the wide ones, and 
let it make an angle of 30 degrees with H. 

Suggestion—An end view must first be 
drawn. 

Exercise 12 —First Angle. Draw the plan 


MECHANICAL DRAFTING 


85 


and elevation of a right circular cylinder of 2 
inches diameter and 5 inches length. The cyl¬ 
inder is placed in a horizontal position, making 
45 degrees with V, backward and to the right. 

Exercise 13— Third Angle. Make three 
drawings of a regular hexagonal pyramid of 
which the altitude is 4 inches, and the edge of 
the base l 1 /^ inches. In the first figure, make 
the plan and elevation showing the base hori¬ 
zontal, and the apex above the base; and place 
the left-hand front edge of the base at 45 degrees 
with V. In the second figure, show the projec¬ 
tions after the pyramid has been revolved 
through 45 degrees about an axis perpendicular 
to V, so that the axis of the pyramid slopes 
downward and to the left. In the third figure, 
revolve the plan of the preceding figure through 
30 degrees clockwise, and construct the cor¬ 
responding elevation. 

Exercise 14— First Angle. Draw the plan 
and elevation of a right circular cone in three 
positions. The diameter of the base is 3 inches, 
and the altitude is 4 inches. In the first posi¬ 
tion, draw the plan and elevation with the cone 
standing on the apex, and with the base 
horizontal. In the second position, draw the 
plan and elevation after the cone has been re¬ 
volved through 60 degrees about an axis per¬ 
pendicular to Y, so that the axis of the cone 
slopes downward and to the right. For the third 
position, revolve the plan of the second position 
counter-clockwise through 45 degrees about a 


86 MECHANICAL DRAFTING 

vertical axis, and construct the corresponding 
elevation. 

INTERSECTION AND DEVELOPMENT. 

75. Intersection. When two surfaces meet 
at an angle so that if either one were extended 
it would actually cut the other surface, the line 
of meeting is called the intersection of the two 
surfaces. 

The line of intersection may be straight or 
curved, according to the nature of the surface. 

Planes, as the simplest kind of surfaces, will 
be considered first. 

76. Development. By the term development 

is meant a figure showing the true size and 
shape of the surface of any given solid, when 
the surface has been rolled or spread out on a 
plane. A true development is obtained when all 
of the surface is made to coincide with a plane, 
without overlapping or folding. Such a de¬ 
velopment, when cut out of paper or thin sheet 
metal, and properly bent or rolled up, will 
reproduce the original solid. 

Some surfaces are truly developable, and 
others are not. Among the former are all sur¬ 
faces composed of planes, as those of prisms and 
pyramids, all cylindrical, and all conical sur¬ 
faces. The most familiar solid which has a non- 
developable surface is the sphere. 

Intersection of Planes 

77. The intersection of two planes is evi¬ 
dently always a straight line. Familiar 


MECHANICAL DRAFTING 


87 


examples of this kind of intersection are to be 
found on every hand. The edge of a box is the 
line of intersection of two adjoining sides, which 
are planes; the ridgepole of a pitch roof is the 
line of intersection of the two sides of the roof; 
and so on in great number. 

78. In Pig. 61, a triangular pyramid stands 
on its base, and several lines of intersection are 
shown. The slanting edges of the pyramid are 
the lines of intersection of the sloping faces. 



Pig. 61. Triangular Pyramid Intersected by a Plane. 

Let X represent a plane seen edgewise* 
Then X is parallel to the H plane, and perpen- 





88 MECHANICAL DRAFTING 

dicular to V. This plane cutting the pyramid 
will intersect all of the inclined faces, giving 
thereby three lines of intersection. The plane 
X, seen edgewise in elevation, cuts the slanting 



Square Pyramid Cut 
Obliquely by a 
Plane. 


edges in points a, b, and c; and these points are 
found in plan directly below on the correspond¬ 
ing edges. 

As the plane cuts edge 0-1 at a, and 0-3 at c, 
it will cut the face 013 in the line joining a and 
c; and, by joining point b with a and c, the other 






MECHANICAL DRAFTING 


89 


two lines are determined, and the whole inter¬ 
section abc completed. 

Two features of the intersection should be 
noted: 

First, it is a triangle. This must always be 
the case when the pyramid is triangular and 
the intersecting plan cuts all three edges, even if 
the plane should not be parallel to the base. 

Second, the sides of the triangle abc are re¬ 
spectively parallel to the edges of the base of the 
pyramid. This parallel relation is due to the 
fact that the plane X in this case is parallel to 
the base. 

79. It may be proved by geometry that if any 
prism, pyramid, cylinder, or cone is cut by a 
plane parallel to the base, the intersection is 
always a figure like the base in shape, and 
parallel to it in position. 

80. Fig. 62 shows the same pyramid with 
the part above plane X removed, showing in 
plan the actual surface cut by the plane. 

81. Fig. 63 is a square pyramid standing on 
its base, and cut by a plane X. The plane X in 
this figure is oblique to H, but the intersection 
abed is found by the same process as before. 
Notice here, that while the intersection has as 
many sides as the base, it is not parallel to it. 

82. Fig. 64 shows a square pyramid in the 
first angle, intersected in a similar way by a 
plane X; it shows also the development of the 
pyramid. 

Let us see how to construct the development. 


90 


MECHANICAL DRAFTING 


Each sloping face of the pyramid is an isosceles 
triangle, and the base is a square; so the develop¬ 
ment will consist of four equal triangles and a 
square, joined together and shown in their true 
sizes. The pyramid may be considered to be 
placed with its vertex at o', the edge o-a at O'-a', 
and the face oab in contact with the plane of the 
paper. Then the triangle oab must be shown 
in its true size at o'a'b'. 


o* 



Fig. 64. Square Pyramid in First Angle, Intersected by a Plane. 
Development of Pyramid Shown at Eight. 


It is then necessary to find the true length 
of the sides of the triangle oab. The H projec¬ 
tion o-b h does not show the true length of the 
line; neither does the V projection o v -b v . Let 
the pyramid be revolved about its axis through 
45 degrees, so that o-b h will move to o-b\. Then 
the line o-b will be parallel to V; and its pro¬ 
jection on V, when found, will show the true 
length of the line. In revolving, the apex 0 will 













MECHANICAL DRAFTING 


91 


not move, and the point b will stay on H; hence 
bh will be projected from b\ to the plane of the 
base or the GL, and o v -b v ! will be the true 
length of the line o-b. 

All of the sloping edges of the pyramid are 
evidently of the same length, and the edges of 
the base are shown in plan in their true lengths; 
so the development may be constructed, laying 
down first the true size of the triangle oab, join¬ 
ing to the edge o'-b' the next face obc, and then 
in turn the other two faces. 

The square, representing the base, may be 
constructed on any short side, as at c'-d'. The 
most expeditious construction is to take a radius 
equal to o v -b v i, strike an arc through a' from 
center o', and on this arc, with the dividers or 
compasses, step off the length a h -b h four times, 
obtaining b', c', d', and a". These points are 
then connected and joined with o'. 

The lines on the development showing the 
intersection of the plane X are next found. The 
point 1, for example, will appear in development 
on the line o'-a' at its real distance from o'. 
This real distance from o may be found in ele¬ 
vation by drawing a horizontal line from l v to 
cut o v -b\ in point V l9 thus determining o v -l V ! as 
the real distance. The reason for this is that if 
the pyramid be revolved about its axis until o-a h 
takes the position o-b\, the V projection will 
then coincide with o v -b V i, and the point 1 will 
appear on o v -b V ! at the same height as before 
revolution. The length o Y -V 1 is then laid off 


92 


MECHANICAL DRAFTING 


from o', giving 1'. The real length from o to 2 
is similarly found by a horizontal line from 2 V 
to 2\. The lengths 0-4 and 0-3 are respectively 
equal to those of 0-1 and 0-2. The points 1', 2', 
3', 4', and 1" are then located and joined, thus 
completing the required development. 

In connection with the construction for 
finding the true length of the line o-b, it should 
be remarked that it is not really necessary to 
think of the entire pyramid as revolving, for the 
same result is reached if the line alone be re¬ 
volved about a vertical axis through o. 



by Plane Perpendicular to H. Corner Cut Off. 

83. A square pyramid like that of Fig. 63, is 
shown again in Fig. 65, but intersected by a 




MECHANICAL DRAFTING 93 

plane Y perpendicular to H. Plane Y is there¬ 
fore seen edgewise in plan. The points of inter¬ 
section a, b, and c are projected to the elevation 
and connected, thus determining the lines a-b 
and b-c. The plane in this position cuts two 
edges of the base and one sloping edge. 

In Pig. 66, the same pyramid is shown again, 
but with the corner cut off. This gives rather 
a clearer idea of the intersection, or section, as 
it is called, cut by the plane Y. 


x 



Fig. 67. Elevation, Plan, and End View of Regular Pentagonal 
Pyramid. 

84. A regular pentagonal pyramid, with ele¬ 
vation, plan, and end view, is given in Pig. 67. 







94 MECHANICAL DRAFTING 

The pyramid has its axis parallel to both V and 
H; hence its base is seen edgewise in both plan 
and elevation. The pyramid is placed in the 
first angle, and the end view is drawn first. In 
this view the base is drawn in its full size. From 
the end view, the front elevation and the plan 
are constructed, the elevation being a view in 
the direction of the arrow. 

The construction of the elevation of the 
pyramid should be apparent from the figure, 
and the plan is drawn by the principles of 
Article 66, which may be again referred to here. 
As the plan is a top view, the width of the base 
will be the same as on the end view. Hence the 
process is to project in the end view the corners 
of the base upon any horizontal line, as A-B, 
and transfer this line with its points of division 
to the position A'-B', directly below the base in 
the elevation. The apex o h may then be located 
and joined with the comers of the base l b 2 b 3 h 4 b 5‘“. 

Let X be a plane at right angles to the base 
of the pyramid. Then the plane in this position 
will intersect the three faces 0-1-5, 0-1-2, 0-2-3, 
and also the base of the solid. 

The plane cuts the edges in the points 
marked a, b, c, and d. These points may be 
found in elevation at the same height, by the use 
of the T-square. Point a, on the edge of the 
base, is located at a T , point b on 0 T -1 T , and point d 
on the base at d T . 

To locate c T , however, it is first necessary to 
fin d c h in plan, then project for C T . The points in 


MECHANICAL DKAFTING 


95 


the end view are projected to A-B at points a u 
bx, Ci, and d x ; and these points are then spaced 
off in the plan at a h , b 2 , c 2 , and d h . The points 
b h and c h are then found by T-square lines on 
0-1 and 0-2 respectively. The section is lined 
in considering the part of the pyramid to the 
right of plane X as removed. 

Intersection of a Plane with a Curved Surface 

85. It has been shown that the intersection 
of a plane with a pyramid or prism is found by 
connecting points in which the plane cuts the 
edges of the solid. In the case of a solid with 
a curved surface, as a cone or cylinder, the only 
edges are the base edges. There may, however, 
be straight or curved lines drawn on the surface, 
and the intersection of the plane with these lines 
be found, thereby locating points on the re¬ 
quired curved intersection. 

86. In Fig. 68 is shown a right circular cone 
standing on its base, and intersected by a plane 
X, which is at right angles with V. The base 
may be divided into any number of parts—in 
this case twelve—and the elements of the cone 
drawn, as 0-1, 0-2, 0-3, etc. These elements are 
cut by the plane in points showing in elevation 
as a, b, c, etc., and these points are then pro¬ 
jected to corresponding elements in plan. 

The points d and m are located in the plan as 
follows: Pass a plane Z through the points d 
and m, and parallel to the base of the cone. 
Then Z will cut the cone in a circle whose diam- 


96 


MECHANICAL DRAFTING 


eter is x-y; and this circle, lying on the surface 
of the cone, will evidently pass through the 
points d and m. The circle x-y is drawn in plan, 
and, by its intersection with the elements 0-4 
and 0-10, fixes the position of the points d and 
m. A smooth curve drawn in plan through the 
points a, b, c, d, etc., is the projection of the re¬ 
quired intersection. The section is an ellipse, 
and its real size and shape are not shown in 
plan. 

We shall now proceed to the development of 



Tig. 68. Right Circular Cone Cut by Plane at Right Angles with V. 
Development Shown at Right. 


the cone and the section cut by plane X. The 
cone may be supposed to be placed with its 
vertex at O', and the element 0-1 at O'-l'; the 
cone is then rolled until all of the curved surface 
has come into contact with the paper. As the 
cone rolls on the plane, the various elements 
will take positions such as o'-2', 0'-3',—0'-6' to 










MECHANICAL DRAFTING 


97 


O'-l", and the edge of the base will develop into 
the curve passing through the points V , 2', 3',— 
1". As all of the elements of the cone are the 
same length, the points 1', 2', 3', etc., will all be 
at the same distance from O'; that is, they will 
lie on the arc of a circle struck from 0' as center. 
The radius of the circle is the true length of any 
element of the cone, as shown by 0-1 in eleva¬ 
tion. The positions of the points 2', 3', etc., are 
found by taking in the dividers the distance be¬ 
tween any two consecutive points of the base as 
seen on H, and laying this off from T twelve 
times. Lines joining these points with 0' will 
represent the positions of the elements in 
development. 

As regards the development of the section 
cut by plane X, the different points of the curve 
may be found on the elements by laying off from 
0' the true distance from the points of intersec¬ 
tion to the vertex 0. The distance 0-a in ele¬ 
vation is a true length, since 0-1 is parallel to V 
(Article 73, e). The point a' is then located at 
once. The true distance of the other points from 
the apex may be found by projecting hori¬ 
zontally from the points in elevation to 0-1, on 
which line their true distances from 0 are shown. 
These distances are then laid off from 0' on tho 
respective elements; and a smooth curve drawn 
through the points will be the section curve 
required. 

Attention is called to the fact that the length 
of the developed base 1', 2', 3',—6'—1" is not 


98 MECHANICAL DRAFTING 

exact, since, in the first place, it is impossible 
with the dividers to measure exactly the length 
of a curve; and in the second place, because it is 
likewise impossible to apply exactly with the 
dividers any given distance along a curve. It 
should be said, however, that by taking points 
sufficiently close together a very good approx¬ 
imation indeed can be obtained. 

87. Fig. 69 shows an example of a cone stand¬ 
ing on its base and intersected by a plane Y 
perpendicular to H. 

Elements of the cone are drawn as before, 
except that it is unnecessary to draw any on the 





Fig. 69. Fig. 70. 

Cone Intersected by Plane Perpendicular to H. 

further side of the cone. In plan, the elements 
are seen to intersect plane Y in points a, b, c, d, 
and e, which are then projected to the elevation 
onto the corresponding elements. It will be 
noticed that in elevation the points a and b are 















MECHANICAL DRAFTING 


99 


quite a considerable distance apart; so two more 
elements are drawn in plan, one between 0-2 and 
0-3, and one between 0-5 and 0-6. These ele¬ 
ments determine two more points on the curve. 
The highest point c cannot be found in elevation 
by direct projection, but is located by a special 
construction. 

A circle with center 0 is drawn on the plan 
passing through c. Considering this circle as 
lying on the surface of the cone, it will intersect 
all of the elements, and will lie in a plane 
parallel to the base. For convenience, the points 
in which the circle intersects the two outside 
elements, 0-1 and 0-7, are used, and projected 
to 0-1 and 0-7 in elevation; then the plane Z is 
the plane containing the circle, and c in eleva¬ 
tion is where Z cuts element 0-4. This section 
curve is shown in its true size and shape in ele¬ 
vation, and is known as a hyperbola, this name 
being given to the curve cut from any cone by a 
plane parallel to the axis. 

88. In Fig. 70 are shown the same cone and 
the same cutting plane Y; but the curve is found 
without the use of any but the two outside or 
contour elements 0-1 and 0-7. The highest point 
c is first determined as in Fig. 68. Other planes 
between Z and the base are then taken. Let 
W be one such plane. Plane W cuts a circle 
from the cone, the diameter of which is x-y. A 
circle with this diameter may then be drawn 
in plan, intersecting plane Y in points b and d. 
These points are in plane W, and hence are 


100 


MECHANICAL DRAFTING 


located in elevation by projecting from the plan 
to plane W. Points on U and on as many other 
planes as may be chosen, are obtained in the 
same way. 



Fig. 71. Cone Cut by Plane Parallel to One Element, Giving Curve 
Known as Parabola. 

Very often this method of construction is 
better than that of Fig. 68, on the score of accu¬ 
racy. By referring to Fig. 68, it will be seen 
that, owing to the steep inclination of elements 
0-3 and 0-5, when b and d are projected from 
the plan, their exact position on 0-3 and 0-5 is 
a matter of some uncertainty. 












MECHANICAL DRAFTING 101 

89. Auxiliary Planes. Planes sueh as Z, W, 
and U, in the last three figures, introduced to 
work out or facilitate some part of the solution, 
are called auxiliary planes. 

90. Still another form of curve results when, 
as in Fig. 71, the cutting plane is taken parallel 
to one element. The plane X, perpendicular 
to Y, is parallel to the element 0-1. The plan 
of the intersection is found by the method of 
Fig. 70. The curve in this case is a parabola, 
in accordance with the definition of geometry, 
that “the curve cut from a cone by a plane 
which is parallel to one and only one element 
is called a parabola.” 

The true size of the section may be found 
by a simple construction. The curve is evi¬ 
dently symmetrical with respect to a line d-z, 
which is the axis of the curve and is represented 
in its true length in elevation. If, now, a view 
of the curve be taken in the direction of the 
arrow, the true size and shape will appear. The 
actual distance between points c and e, for 
example—that is, the true width of the curve 
at that part—is shown in plan as the length 
c-e. The true widths b-f and a-g are similarly 
shown. It will be seen, then, that while in plan 
the true width of the curve at any part is shown, 
the real distances along the axis d-z are not 
there shown. For example, the distance from 
d to line c-e is not a true length. But these dis¬ 
tances along the axis are shown true length in 
elevation, from d to c-e, d to b-f, etc. 


102 MECHANICAL DKAFTING 

Hence, to show the true size of the curve as 
seen in the direction of the arrow, all that is 
necessary is to combine the true lengths of the 
elevation with the true widths of the plan. 
Therefore, at any convenient distance, draw 
m-n parallel to d-z; project with the triangles 
from c, e, b, f, etc., at right angles to m-n; and 
make the widths Cp-e^ bp-fi, and ap-gp, equal 
respectively to c-e, b-f, and a-g, half of each on 
either side of the axis m-n. 

Intersection of a Plane with a Cylinder 

91. A right circular cylinder standing on its 
base and cut by a plane X perpendicular to V, 
is drawn in Fig. 72. The development of the 


TOP 



Tig. 72. Eight Cylinder Cut by Plane Perpendicular to V. 
Development of Cylinder Shown at Eight. 


cylinder is also shown. As in the case of the 
plane cutting the cone, elements of the cylinder 
are drawn, and the points noted in which the 
plane cuts the elements. The base is here 


































MECHANICAL DRAFTING 103 

divided into twelve equal parts, and twelve ele¬ 
ments drawn. The plan of the intersection will 
coincide with the plan of the cylinder, since 
the whole convex surface is projected in the 
circle. 

Development of the Cylinder and of the 
Curve of Intersection. Let the cylinder be 
placed with point 1 of the base at point 1', and 
element A at A', on the plane of the paper. 
Now imagine the cylinder rolled on the paper 
until the entire curved surface has come into 
contact with the paper, and element A is again 
on the paper at A", parallel to A'. The distance 
between A' and A" is therefore the shortest dis¬ 
tance around the cylinder as measured around 
the base. 

As the cylinder rolls from A' to A", the base 
remains always in a plane perpendicular to the 
elements, and hence perpendicular to the plane 
of the paper. Therefore, as the cylinder is 
developed, the edge of the base rolls out in the 
straight line drawn from T perpendicular to 
A' and extending to A". The approximate dis¬ 
tance around the base is laid off in the develop¬ 
ment, by taking the chord of one of the equal 
divisions of the base, and spacing it twelve times 
along T-l", locating the points 2', 3',.. .6'.. .1". 
Lines drawn through these points at right 
angles to the developed base, will be the devel¬ 
oped positions of the numbered elements. The 
lengths of the elements are taken directly from 
the elevation, since the true lengths are there 


104 MECHANICAL DRAFTING 

shown; and a straight line through the upper 
ends of the elements will he the development 
of the top of the cylinder. The development of 
the curved surface of the cylinder is therefore 
the rectangle as shown. 

The development of the section curve is 
obtained by locating the points a, b, c, etc., in 
the development on their respective elements, 
and at the true distance from the foot of the 
element. These distances are all shown in the 
elevation, and consequently may be transferred 
at once to the development; and a smooth curve 
drawn through a', b',... e'... n'... a" will be the 
developed curve. 

Intersection of Solids 

92. Points on the intersection of solids— 
that is, on the intersection of their surfaces— 
are the points in which lines of either surface 
intersect the other. 

93. Visibility of the Lines of Intersection. 

The intersection of two solids, viewed from any 
given direction, is in general partly visible and 
partly invisible. The rule for visibility is that 
visible parts of the intersection must always 
be the intersection of visible parts of each sur¬ 
face. Thus the intersection of the upper parts 
of two surfaces would be visible in plan; while 
the intersection of the upper side of one with 
the under side of the other would not be visible. 

94. Intersection of Solids Bounded by Plane 
Surfaces. When one solid of this class—as, for 


MECHANICAL DRAFTING 


105 


example, a pyramid—intersects another pyra¬ 
mid or prism, the intersection will consist of 
one or two figures bounded by straight lines. 
Points on such an intersection may be deter¬ 
mined by finding where the edges of either solid 
intersect or pass into the faces of the other. 

95. A square prism standing on its base, is 
intersected by a triangular prism with its axis 
parallel to both V and H, Fig. 73. The end 
view at the right shows the left-hand end of the 
horizontal prism. The points in which the 
edges of the triangular prism intersect the faces 
of the other prism, will be shown at once in 
plan, since in plan the surfaces of the square 
prism are seen edgewise. The edge 3-4 inter¬ 
sects the face adef at a point seen in plan as 
m h , and the V projection m T is found in eleva¬ 
tion on 3 y -4 v . 

Similarly, edge 2-6 cuts the same side adef 
at point n. Then the line m-n is the intersection 
of one side 2-3-4-6 of the triangular prism with 
the side of the square prism. In elevation, m-n 
will be a visible line (Article 93). 

The next edge, 1-5, evidently does not inter¬ 
sect the face adef, but cuts the adjoining side 
abgf. The face 1-2-6-5 must then cut both faces 
of the other prism in a broken line, running 
from point n to the point in which the face 
1-2-6-5 cuts the edge a-f, and continuing from 
this point to point q on the face abgf. The point 
where the plane 1-2-6-5 cuts the edge a-f is found 
in the end view. In the end view, a part of 





106 


Fig. 73. Square Prism Intersected lay a Triangular Prism. Development of Prisms Shown at Fight (A and B). 



















































MECHANICAL DRAFTING 


107 


the edge a-f is shown as the T-square line a p -x. 
The plane 1-2-6-5 is seen edgewise in line 1 P -2 P , 
and cuts a p -x at point o. 

The point o on edge a-f is at a distance a p -o p 
higher than the edge 1-5; hence the length 
a p -o p is laid off in elevation above 1-5, locating 
o\ The intersection of face 1-2-6-5 is the broken 
line n-o-q. In a similar way, the under side 
1-3-4-5 breaks around the edge a-f, the point r 
also being located from the end view. The 
figure mnoqrm is the intersection of the tri¬ 
angular prism with the left-hand sides of the 
vertical prism. 

By the same method, the intersection on the 
two right-hand faces is found to be the figure 
stuvw. The visibility of the intersection and 
of the edges of the solids, should be studied until 
perfectly understood. 

Development of the Prism. The square 
prism is shown developed at A, Fig. 73 (the 
ends are not shown in the development). The 
four sides of the prism are equal rectangles 
whose length is shown in elevation, and width 
in plan. Beginning with face abgf, the devel¬ 
oped faces of the prism will appear as the four 
equal rectangles shown in the figure. 

Location of the Intersection on the Develop¬ 
ment. Beginning with face abgf, the points r 
and o, which fall on the edge a-f, are located at 
the same distance from a as in elevation. The 
point q is at a perpendicular distance f h -q h from 
the edge a-f, and at a distance above a-b equal 


108 


MECHANICAL DRAFTING 


to the height x v -q v as shown in elevation. The 
point q' is then located by means of these two 
distances, and then joined with o' and r'. 

Next consider the intersection tuvw on the 
face bckg. Points t and w are located at once 
on the edge c'-k' at t' and w'; and u and v are 
determined in position at u' and v' in the same 
way as for point q. 

It is essential to note that the distance of 
u' and v' from the edge c'-k' must be taken from 
the plan, and not from the elevation. The 
figure t'u'v'w' is the developed intersection on 
this face. 

For the next face, cdek, the points t' and 
w' are already found, and s' may be determined 
as already explained. On the face dafe, the 
intersection develops as shown at o"n'm'r". 

Development of the Triangular Prism. The 
triangular prism is developed at B, in the same 
figure. The method is similar to the preceding 
one, the distances of the points from the end 
of the prism being measured in either the plan 
or the elevation, and the distance from the long 
edges measured on the end view of the prism. 
The corresponding points have been lettered 
the same in both developments. 

96. Intersection of a Prism with a Pyramid. 
In Pig. 74 is shown a rectangular prism inter¬ 
secting a square pyramid. The pyramid stands 
on its base, and the prism has its edges but not 
its faces parallel to the H plane. 

In this case, none of the sides of either solid 


MECHANICAL DRAFTING 109 

are seen edgewise in either plan or elevation; 
hence another view is necessary. This view, 
drawn at X, is taken in the direction of the * 
arrow so as to show the prism endwise; for in 
this position the faces of the prism are seen 
edgewise as straight lines, and the intersection 
may be determined in part as in the pre¬ 
ceding case. 

In the projection X, the base of the pyramid 
is at right angles to the direction of the view 
that is perpendicular to the edges of the prism, 
and the height of the pyramid is the same as 
in elevation. 

In this example, the edges of the pyramid 
and prism have been lettered with capitals, and 
the points when found have been numbered. 
The plan will be adopted of beginning at some 
point, and tracing the intersection around in the 
same direction until completed. 

Starting with the edge A of the pyramid, 
it is found in view X to intersect face FE of 
the prism at point 1, and l h and l v are located. 
Next, B cuts the same face FE in point 2, and 
1 and 2 are joined in plan and elevation, the line 
1-2 being visible in plan and invisible in eleva¬ 
tion. The next edge of the pyramid, C, does 
not cut the face FE. There must, however, be 
an intersection of FE with the side BC of the 
pyramid, since FE cuts the edge B at 2. 

Let it be imagined for a moment that face 
FE is extended in width so that C cuts it at 
m, then a line joining 2 and m would be the 


Fig. 74. Rectangular Prism Intersecting a Square Pyramid. 



110 


) 













MECHANICAL DRAFTING 


111 


intersection of FE with side BO of the pyramid. 
The imagined widening of FE would not alter 
the direction of the intersection, but only the 
length, so the portion 2-3 of 2-m is the actual 
intersection wanted. 

It should also be noted that point 3 is where 
edge E intersects the face BC of the pyramid. 
The intersection is continued on BC by the 
intersection of face EJ of the prism, running 
from 3 to where J cuts the face BC. This point 
on J is found in this way: If a plane parallel 
to the base be passed through J, it will cut the 
pyramid in a square parallel to the base (Arti¬ 
cle 79); and one corner of the parallel square 
is shown in view X as n' on C'; and line S on 
face BC, and parallel to the edge of the base, is 
one side of the square. The edge J intersects 
line S (see view X), and, as line S is on face 
BC of the pyramid, this point (4) is where J 
cuts the face of the pyramid. Point 4 is then 
connected with 3. 

Similarly, by the use of line T, edge Gr is 
found to pierce the face BC at point 5, which 
is the next point of the intersection. The 
remainder of the intersection is found in the 
same way. The visibility in plan and elevation 
is determined as previously explained (Article 
93). 

In projecting the points from the plan to 
the elevation onto the edges B and D, it is diffi¬ 
cult to determine the exact V projections, owing 
to the steep slope of B and D. The position of 


112 


MECHANICAL DRAFTING 


the points in elevation, however, may be tested 
by observing that in view X the perpendicular 
distance of any point from the base is simply 
the height of the point, and the height of the 
point in elevation should be the same. 



97. Intersection of a Cylinder with a Prism. 

Fig. 75 represents the intersection of a circular 
cylinder and an irregular four-sided prism. 
The two are placed in the first angle, the prism 










































































































































































































/ 































ILLUSTRATING THE ELEMENTS OF PERSPECTIVE. 





































































MECHANICAL DRAFTING 


113 


standing on its base and the axis of the cylinder 
parallel to both V and H. 

The intersection in this case will consist of 
three curved lines, one on face AB, one on BC, 
and the third on CD. The cylinder may be con¬ 
sidered as piercing the prism, and points will 
be found in which lines on the cylinder intersect 
the faces of the prism. 

As the cylinder, strictly speaking, has no 
edges parallel to its length, lines or elements 
may be drawn on the cylinder by the aid of the 
half end view shown at the right. This half 
end view is sufficient because the intersection 
on the upper half of the cylinder will be per¬ 
fectly symmetrical with that on the lower half. 
The semicircle is now divided into some num¬ 
ber of equal parts, say six, by the points E, F, 
G, etc., to M; and these points, when projected 
over to the plan in T-square lines, become ele¬ 
ments of the cylinder. These elements are at 
different distances above the center of the cylin¬ 
der, as shown in the end view. Element F is 
at a height F-s above the horizontal center plane 
of the cylinder; element G, at a height G-t; 
and so on. The elements may then be drawn 
in elevation by making them at their respective 
heights above the center. These elements are 
all on the upper half of the cylinder, but a cor¬ 
responding set should be drawn on the lower 
half, by spacing similarly below the center line. 

It is now a simple matter to find in the plan 
the points where the elements of the cylinder 


114 MECHANICAL DRAFTING 

cut the prism, then to project to the elevation 
and obtain the required curve. This construc¬ 
tion is similar to that of Fig. 73. When pro¬ 
jecting the points of intersection from the plan, 
as for example the point where F intersects the 
face AB of the prism, the point on the under 
side of the cylinder, on F\, should also be 
located at the same time. 

It is always important, in such an inter¬ 
section, to find the points in which the cylinder 
cuts the edges of the prism—in this case B and 
C; and if the elements L and G- did not happen 
to pass through B and C, additional elements 
would have to be drawn through B and C, in 
order to determine their exact points of inter¬ 
section with the cylinder. 

Notice carefully the visible part of the inter¬ 
section, which is in accordance with Article 93. 

98. Intersection of Two Curved Surfaces. 
In Fig. 76, a cone standing on its base is shown 
intersecting a cylinder with its axis parallel to 
both V and H. At the left, A is the profile view 
of the cone and cylinder, showing the right- 
hand end of the latter. This view A shows the 
relative position of the cone and cylinder, and 
would be drawn first if the figures were to be 
drawn from given data. 

The distance X-y, for example, is the dis¬ 
tance that the axis of the cylinder is in front 
of the axis of the cone as shown in plan. 

From the position of the solids as shown in 
this view, it may be seen that the intersection 



115 


.fig. 76. Cone Intersecting a Cylinder. Developments of Cylinder and Curve of Intersection Also Shown. 





















































116 MECHANICAL DRAFTING 

will consist of a single closed curve. If, how¬ 
ever, the cylinder were smaller and shown in 
end view entirely within the cone, then there 
would be two separate curves. 

As the cylinder is shown endwise in this 
profile view, the method of solution will be to 
draw lines or elements on the cone, and find in 
the profile view where they intersect the cylin¬ 
der. These points of intersection may then be 
transferred to the plan and the elevation. 

A number of elements of the cone are drawn 
in view A, as o-a, o-b, o-c, o-d, and o-f, o-a and 
o-f being the extreme left-hand and right-hand 
elements which have any contact with the cylin¬ 
der. These elements are next drawn in plan 
by laying off the distances d p -a p , d p -b p , d p -c p , etc., 
from o h along the line X-Y. Through these 
points on X-Y, lines drawn perpendicular to 
X-Y locate points f h , f\, c h , c\, b\ and b\, and 
the elements are then drawn through these 
points and o\ 

The elements may now be drawn in eleva¬ 
tion. The intersection in this case will be ex¬ 
actly symmetrical in plan and elevation with 
respect to the line o-a. This is because each 
element in view A, except o-a, represents two 
elements equally spaced on either side of o-a— 
as o-c and o-c„ o-b and 0-b,; and so on. 

The points of intersection on the right-hand 
half are numbered from 1 to 9 inclusive. Points 
1 and 9 are projected with the T-square from 
view A to element o-a in elevation; points 4 


MECHANICAL DEAFTING 117 

and 6, to element o-d and also to element o-di 
in elevation, thus locating points on both halves 
at the same time; and other points are found in 
the same way. 

With the exception of points 1 and 9, the 
points are then projected directly to the plan 
onto the corresponding elements of the cone. 
Points 1 and 9 are transferred directly from 
the end view to the plan, their horizontal dis¬ 
tances from the axis o p -d p being laid off in plan 
from o h along X-Y. 

Points m and n, where the curve in plan 
touches the outside element of the cylinder, 
might be found the same way as the other 
points. That, however, would require in view 
A an element drawn very close to o-f ; so another 
construction is used. In view A, the center 
plane S of the cylinder will contain both outside 
elements K and L, and will cut from the cone a 
circle S of radius r-t. This circle S is then 
drawn in the plan, and its intersection with K 
gives the points m and n required. This latter 
construction might be used, if desired, in find¬ 
ing the entire intersection. 

Development of the Cylinder. Beginning 
with the element L, which passes through point 
10, and placing 10 at 10i, the outline of the 
cylinder is developed as a rectangle, as in Fig. 
72, except that, instead of making a new divi¬ 
sion of the base into equal parts, the points 
already found are used. Thus the points 9, 8, 
7, 6, etc., are taken from the end view, and 


118 MECHANICAL DEAFTING 

spaced off at 9 1? 8 lt 7 1( etc., in the development. 
The arc between 1 and 10, Fig. A, is divided 
into three equal spaces. The right-hand end of 
the cylinder is made the lower side of the 
development. 

Development of the Curve of Intersection. 

The points of the intersection are located sym¬ 
metrically on either side of X-Y; so X-Y is 
drawn on the development at X'-Y', at the same 
distance from the end of the cylinder as in plan. 

Beginning with point 1 on X'-Y', the dis¬ 
tances from X-Y of the other points, 8, 7, 6, etc., 
are measured in the plan; and then, in the 
development, these distances are laid off on the 
corresponding elements, both above and below 
X'-Y', thus obtaining at once both halves of the 
developed intersection. 

Approximate Developments 

99. Of curved surfaces, it may be said in 
general that only those can be truly developed 
which contain straight lines on their surfaces, 
and which, in addition, when brought into con¬ 
tact with a plane, will touch in only one 
straight line. 

100. It is possible, however, to construct for 
non-developable surfaces one or more figures 
which will have nearly the same total area as the 
given surface, and which, when properly joined 
and bent or curved, may be made to assume 
nearly the shape of the original surface. Such a 
figure is called an approximate development. 


MECHANICAL DRAFTING 119 

Essential Principles of Intersection and 
Development 

101. When a plane cuts one or more lin es, 
an edgewise view of the plane will determine 
the various points of intersection. 

102. If a cone, cylinder, pyramid, or prism 
be cut by a plane parallel to the base, the section 
will always be a figure parallel to the base and 
similar to it in shape. 

103. The intersection of a plane with a 
curved surface is determined by means of the 
points in which the plane cuts lines on the sur¬ 
face. These lines may be either straight or 
curved, according to the nature of the surface. 

104. The intersection of two surfaces is 
determined by means of the points in which 
lines on either surface intersect the other. 

105. For the intersection of two surfaces, 
the points are first found in the projection which 
shows an end view of one of the solids. Two 
such end views may be necessary. 

106. A development shows the true length of 
any line, straight or curved, which lies on the 
given surface. 

107. A right circular cone develops into a 
sector of a circle, in which the radius is equal 
to the length of an element of the cone. 

108. A right circular cylinder with both ends 
parallel will develop into a rectangle, whose 
length is that of the cylinder and breadth is 
equal to the circumference of the base. 


120 MECHANICAL DRAFTING 

PRACTICAL PROBLEMS 

109. We shall now make some applications 
of the principles of intersection and develop¬ 
ment to the solution of practical problems. 

PROBLEM 1 

Given Cross-Section of Gutter, and Pitch of 
Roof, to Find Cross-Section of Rake 
Moulding which will Miter 
with Gutter 

Let the cross-section of the gutter be as 
shown in A T , Fig. 76A, and let the slope of the 
roof be 30 degrees. The angle of miter, as given 
in the plan, is 45 degrees. Lines drawn from 
a v , b v , c v , and d T , parallel to the pitch of the 
roof, will represent edges of the raking mould¬ 
ing, these same edges being shown in plan 
parallel to the V plane, which may here be con¬ 
sidered as the end wall of the house. 

To find the cross-section of the moulding is 
an application of the principles just studied. 
A plane cutting the moulding at right angles 
to its length will show the true cross-section 
required. 

As the edges of the moulding are parallel 
to Y, the cross-section plane will be perpen¬ 
dicular to V, and will be seen edgewise on V. 
It may be taken at any convenient distance from 
the gutter, as in the position X-Y. This plane 
will intersect the edges drawn from a, b, etc., 
in the points n, m, p, and t. Since the surface 


MECHANICAL DEAFTING 121 

between p and t is curved, it will be necessary 
to make use of lines drawn on the curved sur¬ 
face, starting from points such as 1, 2, and 3 



Fig. 76A. Finding Cross-Section of Moulding to Miter with Gutter. 

on the curved outline of the gutter. The plane 
X-Y cuts these lines at the points q, r, and s. 
The plan of the section cut by plane X-Y is 




















122 


MECHANICAL DRAFTING 


not the true size and shape, since plane X-Y 
is not parallel to H (Article 54). 

If plane Z represents the plane of the end 
of the house, then the edge of the moulding 
drawn through d is in this plane; and the other 
points of the cross-section, m, p, q, etc., stand 
out from this plane the distances which are 
shown in plan from m h to Z, from q h to Z, etc. 
Hence, if plane X-Y be revolved about an axis 
in plane Z, the distances from Z, as m h -5, n h -6, 
q h -7, and so on, will revolve at right angles to 
X-Y; and when the plane of the section coin¬ 
cides with Z, the distances will show on V in 
their true lengths at m T -m', n 7 -n', etc. This 
process worked out for each point will give 
n', m', p'... ,t T as points on the outline of the 
section as seen lying on Y, and hence shown in 
its true size and shape. The back edge n'-s 7 
may be drawn at any convenient angle. The 
figure n', m'. . .r'. . .t 7 is therefore the required 
cross-section. 

If, in a problem like this one, the miter is 
at the usual angle of 45 degrees, there is a very 
short construction as follows: Let the horizon¬ 
tals c 7 -ll, 1 7 -12, 2 V -13, and 3 T -14 be drawn. The 
line 1 T -12, for example, is equal to l h -15 1 ‘; and, 
as the miter is 45 degrees, l h -15 h is equal to 
d h -15 h ; that is, 1 T -12 is equal to d h -15\ Hence, 
if the distance l v -12 is taken and laid off from 
q T at right angles to X-Y, the point q' on the 
true size will be determined. 

In the same way, it may be seen that b T -10 


MECHANICAL DRAFTING 


123 


is equal to m v -m'; 2 V -13 to r^r 7 , and so on. Hence 
the short construction for finding the true 
cross-section is to draw the horizontals b v -10... 
l v -12.. .3 V -14, and lay off these distances from 
X-Y as shown. 

PROBLEM 2 

To Construct the Development of a Sheet-Metal 
Moulding 

Pig. 76B shows a moulding mitered at both 
ends. The elevation is given complete, and the 






Fig. 76B. Moulding Mitered at Both Ends. 

plan shows the miter at the left end. The sur¬ 
face of the moulding is partly curved, and partly 

























124 


MECHANICAL DRAFTING 


plane. To make the development, proceed 
according to the principles of the development 
of a cylinder, under Article 91. 

Since the moulding is symmetrical at both 
ends, a center line X-Y, from which to take 
measurements, is drawn in elevation. The given 
moulding miters with two others at right angles 
to it on miter planes at 45 degrees; hence the 
three mouldings are alike in cross-section. The 



Fig. 76C. Development of a Sheet-Metal Moulding. 

curved outline at either end of the given mould¬ 
ing must represent the true shape or end view 
of the other moulding, as each other moulding 
is perpendicular to the given one. The curved 
outline at either end is then also the true cross- 
section of the given moulding, and the width 
of the developed moulding will be equal to the 
length of the line a, b,... e,. .. k. 

The development is drawn in Pig. 76C, where 
X'-Y' represents the position of X-Y, and the 
width 1'... .9' is equal to the length a, b,. . .e 
. . * k t The lines c-c, d-d, e-e, and h-h are lines 













MECHANICAL DRAFTING 


125 


drawn on the curved surrace in order to get the 
development. 

The distances a-b, b-c, c-d, d-e, and so on, 
to the point k, are then laid oft along X'-Y', 
giving the points T, 2',.. .5',.. .9'; and through 
these points, lines are drawn indefinite in 
length and perpendicular to X'-Y'. On these 
lines, the half-lengths 1-a, 2-b, etc., taken from 
Fig. 76B, are laid off, locating the points a'a', 
b'b', c'c', up to k'k'. These points, when joined, 
give the ends of the required development. 

PICTORIAL DRAWING 

110. Graphical representations which give 
more or less of a picture effect, are sometimes 
very useful adjuncts to practical drafting. 

To the untrained eye, such a drawing—of a 
building, for example—conveys a much clearer 
idea than plans and elevations. The same would 
be true of any other complicated structure. 
These pictorial drawings are of various kinds, 
as perspective, oblique projection, and isometric 
drawing. Of these three kinds, the first alone 
is the true picture drawing showing the actual 
appearance of any object as seen by the nat¬ 
ural eye. 

. Unfortunately, however, the principles of 
perspective, while not difficult, are harder to 
acquire than those of oblique projection or 
isometric drawing, and the process of construct¬ 
ing an accurate perspective drawing is longer 
and more tedious. 


126 


MECHANICAL DRAFTING 


It is also true that in many cases the some¬ 
what distorted isometric or oblique projections 
will supply to the mind all the pictorial assist¬ 
ance that is necessary. The present section of 
this treatise will deal principally with isometric 
drawing and oblique projection. 



111. For the sake of comparison, the same 
cabin Ms been shown in Figs. 77, 78, and 79, in 
the three different ways, Fig. 77 being a per¬ 
spective view; Fig. 78, an isometric drawing; 
and Fig. 79, an oblique projection. In all three 


















MECHANICAL DRAFTING 


127 


views, the vertical edges of the cabin are drawn 
as vertical lines, and therefore parallel. 

In Figs. 78 and 79, all the other lines and 
edges which are actually parallel in space are 
drawn as parallel lines; but in the perspective 
of Fig. 77, the other lines which are really 
parallel in space are drawn as converging 
lines—as, for example, the edges of the roof and 
the ridge, the top of the doorway, etc. 



Fig. 81. Simple Isometric Eep- Fig. 82. Illustrating Direction 
resentation of a Cube. of View for Isometric 

Drawing of Cube in 
Fig. 81. 

Isometric Drawing 

112. The principles of isometric drawing are 
best illustrated by reference, first, to a simple 
rectangular object as a cube or square prism. 
In such a solid there are three sets or systems 
of parallel edges; and in the simplest isometric 
drawing, these edges are drawn in three fixed 










128 


MECHANICAL DRAFTING 


directions, respectively parallel to what are 
called the isometric axes. These three axes are 
shown in Fig. 80, B vertical, and A and C at 
30 degrees with the horizontal. 

In any isometric drawing, lines parallel to 
the isometric axes are drawn in their true 
lengths. 

113. The simplest isometric representation 
of a cube is shown in Fig. 81, except that ordi- 



Fig. 84. Isometric Drawing of 
Post and Sill, Showing 
Mortise and Tenon. 



Fig. 83. Isometric of a Joist. 


narily the dotted edges are omitted. All of the 
edges in this figure are full-length, and are 
either vertical or at 30 degrees with a hori¬ 
zontal. The drawing represents the cube in the 
position of Fig. 82, with the view taken in the 
direction of the diagonal of the cube, as indi¬ 
cated by the arrow. That that is the direction 













ILLUSTRATING VANISHING POINT AND NECESSITY OF DRAWING OBJECTS IN PROPORTION. 
Two men of same actual height, but oue iu background appears much the taller. 
















































































































































MECHANICAL DRAFTING 


129 


of the view, is shown in Fig. 81, from the fact 
that the lower back corner of the cube is directly 
behind the upper front corner a. 

The isometric view may be taken through 
either corner a or c, but always in the direction 
of a diagonal of the cube. Note that while the 
edges are shown in their true lengths, the angles 
are not shown in their true size. 

Isometric drawing is especially appropriate 
for showing framing, mortises, tenons, etc. 

114. A simple isometric is given in Fig. 83, 
where a piece of joist is shown ready for halving 
together with two other pieces. 

115. The isometric of a post and sill, show¬ 
ing a mortise and tenon, is drawn in Fig. 84. 

116. To Draw an Isometric from a Given 
Plan and Elevation. Let A v and A h , Fig. 85, be 







/ 


/ 


Fig. 85. Drawing an Isometric of a Miter Eox from Given Plan 
and Elevation. 

the elevation and plan of a wooden miter box, 
and let 0 be chosen for the lowest corner of the 



















130 


MECHANICAL DRAFTING 


isometric. Then the horizontal edges of the box 
will be 30-degree lines in isometric; the vertical 
edges, vertical lines; and the real lengths will 
be shown (compare Figs. 81 and 82). Then, 
from O' draw a 30-degree line to the right, equal 
to the length; one to the left, equal to the width; 
and one vertical, equal to the given height. 

The rest of the box may then be drawn, 
showing the thickness of the bottom and sides. 
The 45-degree saw-cut c-d, as shown in plan, is 
transferred to the isometric by simply laying 
off from f' and e' respectively the distances f-c 
and e-d, and joining c' and d' across the top of 
the box. The vertical cut showing on the sides 
of the box is then drawn in. 

117. Simple rectangular objects, as those of 
Figs. 83, 84, and 85, can usually be drawn at 
once from given dimensions without reference 
to plan or elevation. In more complicated cases, 
however, the plan and elevation are generally 
desirable, and often they are necessary. 

118. Non-Isometric Lines. Non-isometric 
lines are those which cannot be shown parallel 
to the isometric axes. This classification em¬ 
braces oblique straight lines and also curves. 

An oblique line may be located in isometric 
drawing, by fixing the position of the ends of 
the line by co-ordinates; and the isometric of 
a curve is made by locating a sufficient number 
of its points in isometric by means of co-ordi¬ 
nates, and then drawing a smooth curve through 
these points. 


MECHANICAL DRAFTING 


131 


119. Fig. 86 shows plan and elevation of a 
prismatic block with two faces cut off obliquely. 

To construct the isometric, let d be taken as 
the lowest corner of the isometric, and located 
at d'. The base may readily be drawn with the 
edges as 30-degree lines. The lines b-c and a-f 
are oblique, and cannot be drawn in isometric 



at the same angle. Point c may be located at 
once, since d-c is a vertical line. Point b 
is located in projection by means of the 
horizontal distance d v -bi, and the vertical height 
b x -b\ 

These lines will show parallel to the isomet¬ 
ric axes, and may be laid off in their true 
lengths. Hence, from d 1 , lay off d 1 -^, equal 
to d v -b x , and erect the vertical line b 2 -b x , equal 
to bi-b v , thus locating point b 1 . 

The point a 1 is determined in a similar way 
















132 


MECHANICAL DEAFTING 


by means of the co-ordinates d 1 ^, equal to 
d v -ai, and a 2 -a x equal to ai-aL The left-hand 
side may then be completed. Next the 30-degree 
edges from a 1 , b 1 , c 1 , and d 1 are made equal to 
the thickness, and the edges of the back then 
drawn in and the isometric completed. 


d v 




Fig. 87. Drawing a Wedge-Shaped Block in Isometric. 

120. To draw a wedge-shaped block in iso¬ 
metric, refer to Fig. 87. The base is drawn in 
isometric as before, and the vertical edges may 
be drawn immediately, obtaining points b l , e l , 
etc. The point c 1 is located in isometric by 
means of three co-ordinates or distances, taken 
from the projection. First, the horizontal dis¬ 
tance a h -n, laid off at a^n 1 ; second, another hori¬ 
zontal distance c h -n drawn at n’-c 2 ; and third, 
the vertical height c^c', laid off at c 2 -c\ The 
point c 1 is thus fixed in position by the three 



















MECHANICAL DEAFTING 133 

co-ordinates parallel to the isometric axes. The 
rest of the figure may then be easily finished. 

121. Isometric of Curved Lines. Points in 
the isometric of circles or other curved lines, 
are also determined by means of co-ordinates 
parallel to the isometric axes. 

122. A cube having one circle traced on the 
top and another on the front, is given in Pig. 
88. Taking 0 at O', the isometric of the cube 



rig. 88. Illustrating Isometric of Curved Lines. 


is drawn. The circles will then be constructed 
in the top and the left front side. 

Taking first the smaller circle in the top, 
divide it into any number of equal parts, as 
eight in the figure. The points might be located 
by means of co-ordinates from the front edge 
a-b of the square; but it is better to refer them 
















134 MECHANICAL DRAFTING 

to the horizontal center line of the circle (8-1), 
which, when produced, is the diameter m-n of 
the square. Next draw the other diameter of 
the square passing through 4-5. The two diam¬ 
eters are drawn in the isometric, and points 1 
and 8 are located on m^n 1 by laying off d 1 -! 1 
and d 1 ^ 1 equal to the radius, and points 4' and 
5' are then found on the other diameter at the 
same distance from the center d 1 . 

In the plan, lines 2-3 and 6-7 are parallel to 
the diameter 4-5, and will be shown parallel to 
4 1 -5 1 in isometric. From the center d 1 , mark 
off on m 1 -!! 1 the distances d 1 -© 1 and d 1 -! 1 , equal 
respectively to d-e and d-f; draw 2'-3 r and 6'-7'; 
and lay off both ways from e 1 the distance e-2, 
thus fixing 2' and 3'. The same distance is laid 
off from f 1 , locating 6' and 7'. 

The ellipse, which is the isometric of the 
circle, is then drawn through the points. The 
axes of the ellipse will lie on the diagonals of 
the isometric square. 

The larger circle in the vertical face of the 
cube is similarly constructed, using the hori¬ 
zontal diameter p-r and the ordinates as shown 
in the figure. The axes of this ellipse will like¬ 
wise lie on the diagonals of the face of the 
cube. 

123. Isometric of a Vertical Cylinder. The 

plan of the cylinder is shown at A, Fig. 89. The 
first step is to circumscribe a square about the 
circle, with the sides respectively parallel and 
perpendicular to a T-square line. As this is a 


MECHANICAL DRAFTING 135 

plan of the cylinder, the sides of the square will 
be 30-degree lines in isometric. 

Let 0 be placed at O', and the isometric 
square drawn. The circle of the base is then 
drawn as in the preceding case. Prom each 
point in the base, vertical lines are drawn equal 
to the desired length of the cylinder, thus locat¬ 
ing points on the circle of the upper end. The 




Fig. 89. Drawing Isometric of a Vertical Cylinder. 

two vertical lines on the outside will be tan¬ 
gent to the bases, and will form part of the 
outline. 

124. Isometric of a Cone. Let it be required 
to draw a right circular cone with its axis hori¬ 
zontal. If the axis is horizontal, the base will 
be vertical. Hence, draw an elevation of the 
base at A, Pig. 90, and circumscribe a square. 
Let 0 be placed at O' and taken as the lowest 
comer of the isometric. As A is an elevation, 
two sides of the square are vertical lines, and 
must be so drawn in the isometric. The iso- 














136 


MECHANICAL DRAFTING 


metric circle is then drawn as before, using the 
diameters of the square and the given co-ordi¬ 
nates. 

A line drawn from the center of the base at 
30 degrees to the left, will represent the axis, 




Tig. 90. Drawing a Cone in Isometric. 

which is perpendicular to the plane of the base. 
On this axis the desired altitude of the cone is 
laid off, locating the apex b'. Lines drawn from 
b' tangent to the base, complete the view of the 
cone. 

NOTE—Although only eight points have been used 
for the circles in the given figure, for larger figures or 
for more accurate results more points would be necessary. 

125. The isometric of a wooden bracket is 
shown at B in Fig. 91. At A are drawn two 
views—the front elevation, and the left side 
elevation giving the thickness. The isometric 
is constructed as shown in the figure. 












MECHANICAL DRAFTING 137 

Oblique Projection 

126. Oblique projection differs from isomet¬ 
ric drawing in that one face of an object is 
usually represented in its true size and shape 
as if parallel to the plane of the drawing, while 
the edges perpendicular to this face are drawn 
at any convenient angle, as 30,45, or 60 degrees, 
either to the right or left. 

In Fig. 92 are shown the three angles of 
inclination for the case of a cube. 

Cavalier or cabinet projection is the term 



Fig. 91. Drawing the Isometric of a Wooden Bracket. 


applied to oblique projection when the 45-degree 
inclination is used. 

The lines in oblique projection correspond¬ 
ing to the isometric axes, are as shown in Fig. 
93, one vertical, one horizontal, and one oblique 
(in this figure 45 degrees). Any line or edge 
which can be drawn in oblique projection paral- 




















138 MECHANICAL DBAFTING 

lei to the 45-degree line, will be shown in its 
true length. 



d 



Fig. 93. Lines in Oblique Pro¬ 
jection Corresponding to 
Isometric Axes. 




jection of a Cube. 


This system of representation is perhaps a 
trifle simpler than isometric, since not only all 
lines parallel to o-a or o-b are shown in their 
true lengths, but also all lines parallel to the 
plane of o-a and o-b. 

On account of this property, an oblique pro¬ 
jection is often more easily made than an iso¬ 
metric—as, for instance, in the case of circles 
or curves which lie in a plane parallel to the 


















MECHANICAL DRAFTING 


139 


plane of the drawing. Lines which are neither 
parallel nor perpendicular to the plane of the 
front face of the object, must be located by 
means of properly chosen co-ordinates, as in the 
case of isometric. 



Fig. 95. Square Post Partly 
Out Away on Front 
and Sides. 


127. Two pieces of joist with the ends cut 
for halving together, are shown in Fig. 94. All 
of the edges are either parallel or perpendicular 
to the plane of the front face, and are therefore 
shown true length. 

128. Fig. 95 show r s a square post, with parts 
cut away on the front and side. 

129. A short piece of moulding is repre¬ 
sented by oblique projection in Fig. 96. The 
curves of both the front end and the back end, 
are shown in their true size and shape. From 













140 MECHANICAL DEAETING 

such a drawing, a plan and elevation might 
readily be constructed. 

130. An arch with a skew face is shown in 
plan and elevation in Fig. 97. This case will 
illustrate the use of co-ordinates in the con¬ 
struction of the oblique projection. As the front 
face of the arch which is projected in the line 



Fig. 97. Arch with Skew Face. 

& h -z b is not horizontal, it will not be shown true 
size in the oblique projection, and the various 
points must be determined by co-ordinates. 
First draw through z h a horizontal line, and 
produce a"b b to meet it at o h , and take the posi¬ 
tion of o h at o' for the oblique projection. Then 
o'z' represents o h z h . 

Next, a' is located on the 45-degree line 
through o', at a distance equal to o h a". The line 
joining a' with z' is the base line of the face of 
the arch. 

To locate the front faces of the arch stones, 

























MECHANICAL DRAFTING 141 

proceed as follows: Point c' may be found 
immediately by making the vertical line a'-c' 
equal to a v c v , and a vertical through z' of the 
same length will give one corner of the left- 
hand stone. It is desirable to locate the remain¬ 
ing corners with reference to the center line 
through 1', since the points are symmetrically 
located on either side. 

The next point d, together with the sym¬ 
metrical point on the left side of the arch, is 
at a distance from the center line equal to 1-2. 
This distance is in the plane of o h z h , and so will 
be laid off in its true length at l'-2'. Next, the 
point d is at the perpendicular distance 2 h -d h 
from the vertical plane of o h z h , and this distance 
will appear as the 45-degree line through 2', 
locating a point m' on the base line of the front 
face of the arch. The point d' is then found in 
a vertical line through m' at a height equal 
to m v d\ 

Next in turn, e' is located by the vertical line 
through d'; and f' found by the co-ordinates 
l h -3 h , 3 h -n h , and n v -f T . 

The rest of the corners are located similarly. 

Since parallel lines must show parallel in 
oblique projection, the lines p'-r 7 , e'-f', s'-t', 
c'-d', u'-x', and a'-z' should all be parallel. The 
long edges of the stones are drawn back at 45 
degrees, their lengths being taken directly from 
the plan. 

As the back end of the arch is in a plane per¬ 
pendicular to the length, it follows that if it 


142 


MECHANICAL DKAFTING 


were all drawn in, it would be of the exact size 
and shape of the given elevation. 

In fact, a more direct method of construction 
for the oblique view would be to construct the 
back end first, true size and shape; then, from 
each point, draw lines forward at 45 degrees, 
with lengths equal to the lengths in plan. This 
short construction, of course, would not be ap¬ 
plicable if the back face had any other direction. 

131. The reader should work out the follow¬ 
ing exercises for himself. 

Exercises for Practice 

(a) Draw an isometric view of a circular 
cylinder 2 inches in diameter and 4 inches long, 
placed with the axis horizontal. Show the ele¬ 
ments of the cylinder running backward and to 
the right. Show a square hole % inch in 
diameter cut through the center of the cylinder 
from end to end. 

(b) Draw the isometric of a regular hex¬ 
agonal pyramid when the base is in a vertical 
plane. Take for the lowest corner of the 
isometric, point 0 as indicated in the elevation, 
Pig. 98. Make each edge of the base l 1 /^ inches 
long, and the altitude of the pyramid 4 inches. 

(c) Make the isometric of the stairs shown 
in Fig. 99, taking 0 as the lowest corner of the 
isometric. Scale, y 2 in.=l ft. 

(d) Make the isometric of the moulding 
shown in cross-section in Pig. 100, taking 0 as 
the lowest corner* Make the length of the 


MECHANICAL DRAFTING 


143 



agonal Pyramid with 
Base Vertical. 



K-3’ - M 



Fig. 99. Stairway. 



Fig. 100. Cross-Section of Moulding. 



























144 MECHANICAL DRAFTING 

moulding 8 inches. This may be drawn half¬ 
size, if desired. Before drawing the isometric, 



the section must be drawn from the given 
directions. 

(e) Draw in oblique projection a right cir¬ 
cular cone standing on its base. The diameter 



of the base is 2 inches, and altitude is 4 inches. 

(f) Make the oblique projection of the 
frustum of a cone, which is shown in elevation 












































































■ 









































AN EXAMPLE OF PARALLEL PERSPECTIVE. 












































































































































MECHANICAL DRAFTING 


145 


in Fig. 101. Tlie axis of the frustum is 3 ]/ 2 
inches long. 

(g) Draw the oblique projection of a 
wooden box, of which an end view is shown in 
Fig. 102. The length is 12 inches. The box, 
including the cover, is made of %-inch stock, 
with the ends nailed onto the sides, and the bot¬ 
tom nailed to the ends and sides. Make the 
drawing one-quarter size. 

(h) Draw in oblique projection the metal 
bathtub shown in Fig. 103, disregarding the 
thickness of the metal. Show the length hori¬ 
zontal, and the width at 45 degrees. Scale 1 
inch=l ft. 

PRACTICAL DRAFTING 

The Draftsman’s Qualifications 

132. Before taking up the subject of work¬ 
ing drawings, a few words may be said concern¬ 
ing the draftsman himself. 

There are draftsmen good, bad, and indif¬ 
ferent. There is the man who apparently has 
no concern about his employer’s interests, yet 
perhaps wonders why his salary does not in¬ 
crease. Another type is the man who, although 
able to make mechanically an excellent draw¬ 
ing, is nevertheless but little better than an 
animated drafting machine. He can make a 
drawing when he has explicit directions to fol¬ 
low; but alas for the drawing when there is to be 
a little brain supplied! 

Last and best is the real draftsman—the one 


146 MECHANICAL DRAFTING 

who is alive and alert, and whose hands and 
brain work in conjunction. He is well-grounded 
in the theoretical principles of his work; he is 
the man who knows the “why.” He must be 
painstaking and ready to learn. Sloppy and 
careless work is inexcusable in a draftsman. 
As has been said by a leading architect of the 
young man just entering the profession, “He 
must be prepared to draw heavily on his common 
sense.” He must learn to use his time with dis¬ 
crimination. In many cases, time spent in 
securing great accuracy or fine finish in a 
drawing is time wasted. 

The position of draftsman, if successfully 
filled, may often be the stepping-stone to some¬ 
thing better. The one who is best serving his 
employer’s interests, and thereby fostering his 
own, will not be content to do or know only what 
is absolutely required. He will broaden his 
mind and increase his own value by acquiring 
some knowledge of related lines of work. He 
will, in short, be prepared so that when a 
vacancy occurs higher up, he will be just the 
one to receive the promotion. 

133. Employer’s Point of View. The man 
who makes his business a success necessarily 
looks at the commercial value of the draftsman’s 
work, and very soon learns who is making good, 
and who may be relied on. In these times of 
strenuous competition, the margin of profit is 
often narrow; consequently the employer will 
advance those who make his success possible, 


MECHANICAL DRAFTING 


147 


and dispense with the services of those who have 
no interest beyond their own salaries 

WORKING DRAWINGS 

134. A working drawing is one which is de¬ 
signed for actual use in the shop or field. It is 
the drawing which goes out from the drafting 
room, and which conveys to the mechanic or 
builder instructions as to the machine, bridge, 
building, or other construction which is to be 
made. It must contain all the different views 
and dimensions necessary to enable the work¬ 
man to go ahead and construct the thing 
required. 

In order that the drawings may be readily 
understood by the mechanics, they must be made 
in accordance with customary drafting practice. 

135. Detail Drawings; Assembly Drawings. 
For objects of more or less complicated struct¬ 
ure— as buildings or machines—two kinds of 
drawings are necessary: the detail drawings, 
showing different parts separately; and the 
assembly drawings, showing the object as a 
whole. 

If drawings are required of some object 
which is already constructed, in order that dup¬ 
licates may be made, then preliminary drawings 
or sketches are first made. Dimensions and 
measurements are made directly from the 
object, and placed on the preliminary drawings 
or sketches. It is especially important that 
these sketches shall contain all necessary views 


148 MECHANICAL DRAFTING 

and dimensions, as the object in question may 
be miles away from the drafting room, and the 
sketches are the draftsman’s sole guide when 
making the final drawings. 

For making these sketches, the draftsman 
should have a pad or notebook of cross-section 
paper, one or two triangles, a compass, a two- 
foot rule, and a pair of calipers. 

When an object is to be made for the first 
time, the design is first prepared by the engineer 
or designer from a consideration of the neces¬ 
sary relations between the different parts and 
the requisite properties of the same. The head 
draftsman may then take the design, and work 
up the necessary details to a point where the 
drawings can be finished by the other draftsmen. 

136. An important requirement which should 
be kept in view in making working drawings is 
clearness. The drawing should have but one 
meaning. To this end, enough views must be 
given, so that for the object represented no un¬ 
certainty shall exist as to its shape and 
proportions. 

These different views should be placed near 
enough together, so that they may be readily 
compared, but not so close that there will be any 
tendency to confusion. When certain necessary 
information cannot be conveyed by the drawing 
alone, explanatory notes must be given on the 
same or another sheet. 

137. Kinds of Lines. Drawings are easier 
to read, and the meaning is made clearer, by the 


MECHANICAL DRAFTING 


149 


use of several kinds of lines, differing according 
to the purpose for which the line is to be used. 
The conventional types of lines for various pur¬ 
poses are shown in Fig. 104. The full line and 
the dotted line should be of the same width; the 
center line, dimension line, and construction line 
should all be of the same width, and narrower 

Full. L /a/e - - - 

Dotted L/ne —-— —. 

Center L/aje - 

D/me ns/on L/ne - -- 

Extension L/ne - 

Shade Line — ——■— ■ 

Construction L/ne - 

Fig. 104. Conventional Lines Used for Various Purposes in 
Mechanical Drafting. 

than the first two; the extension line should be 
fine, and the shade line heavy. 

For the broken lines, there is no standard 
length for the long or short dashes; but for a 
neat and properly made drawing, the short 
dashes of the so-called dotted line should be of 
equal length; and similarly, for all the broken 
lines, the like dashes when repeated should be of 
uniform length. 

Many draftsmen are careless about their 
dash and dotted lines, with the result that their 
drawings are very likely to have a slovenly 
appearance. 













150 MECHANICAL DRAFTING 

138. Shade Lines. These are heavy lines, as 
shown in Pig. 104, applied to certain parts of 
the drawing. They are used principally for the 
sake of imparting character and relief to the 
figures. Shade lines are not essential, and in 
some drafting offices are dispensed with almost 
altogether. They do, however, give to a draw¬ 


a 

a 

PLAN 


1 —1 

rn 

1 

£ LEV AT/ ON 



nn 

PLAN 

m 

XJJ 


ee £ VAT/ON 
Fig. 106. 


Fig. 105. 


Illustrating Use of Shade Lines. 


ing a certain finish which would otherwise be 
lacking, and in some cases materially assist in 
making clear the object represented. 

How Shade Lines are Used. Theoretically, 
shade lines are the lines or edges which separate 
light from dark surfaces; practically they are 
applied to certain lines of the drawing according 
to a conventional system. Shade lines are ap¬ 
plied only to lines which represent edges of an 
object; and, in the system most generally 
adopted, the right-hand and lower edges in both 
plan and elevation are the shaded lines. 

Examples of Shade Lines. In Pig. 105 is 
shown a stick with rectangular pieces projecting 












MECHANICAL DRAFTING 


151 


up from the surface. The right-hand and lower 
edges of the stick are shaded in both views; and 
in the plan, the right-hand and lower edges of 
the two uprights are also shaded; while in the 
elevation, only the right-hand edges are made 
shade lines. 



i-! 


Fig. 107. Fig. 108. 

Illustrating Shading of Circles. 

Pig. 106 represents the same stick with holes 
instead of uprights. Notice, in the plan, the 
change in the position of the shaded edge. This 
is in strict conformity with the rule, since the 
upper and left-hand edges of the opening are 
the lower and right-hand edges of that portion 
of the object. It is in cases like these that shade 
lines have practical value in assisting to make 
clear the actual meaning of the drawing. 

Shading of Circles. The shade line of a circle 















152 


MECHANICAL DKAETING 


always begins and ends on a 45-degree line, as 
shown in Fig. 107 and 108, the 45-degree line in 
this position marking the division between what 
may be called the lower and right-hand edge 
and the upper and left-hand edge. The shade 
line begins at the extremities of the 45-degree 
diameter, with the same width as the unshaded 
part, and gradually increases in width. This 
smooth and pleasing effect is produced by 
drawing the other 45-degree line, a-b, shifting 
the center c slightly to c', and, with the same 
radius, drawing over the part to be shaded. 

The excess width of a shade line over the 
ordinary line is generally placed on the outside 
of the area inclosed by the figure. Exceptions 
occur when the placing of the shade line in this 
position would unduly distort the figure or tend 
to produce a jagged effect. 

139. Blue-Prints. The form in which a 
working drawing goes out from the office to the 
shop, or field, or wherever the actual construc¬ 
tion is to be made, is the blue-print. The steps 
which lead up to the final form of blue-print are: 
first, pencil drawing; second, tracing; and third, 
the blue-print. Sometimes the second step is 
omitted, as will be explained later. 

Assuming that the preliminary sketches are 
made, a scale at which the drawings are to be 
made is then chosen. The particular scale to be 
used is determined by various considerations. 
The drawing should be on a scale large enough 
so that the different views and dimensions may 


MECHANICAL DRAFTING 


153 


be clearly read; but, on the other hand, they 
should not be unnecessarily large and unwieldy. 
Various scales are used in engineering and 
machine work. Sometimes certain parts or 
pieces are drawn greater than full size. In this 
country, common architectural practice is to 
make drawings at a scale of *4 in.=l ft., with 
details at % in.=l ft., and also details at full 
size. 

The scale decided upon, the center lines of 
the various views are laid out, the outlines 
blocked in, and then the details supplied. 
Where the different views are on the same sheet, 
the constructions of each should be carried on at 
the same time. 

The pencil drawing may be made on brown 
duplex paper, on thin white bond, or on tracing 
cloth. No matter which kind is used, the lines 
should be bold and distinct; and to this end, the 
pencil used should be not harder than 3H, and in 
some cases softer. 

The Tracing. If the penciling is done on the 
duplex paper, a tracing is next made. This is 
done in ink on the tracing cloth, which for this 
purpose is tacked on the board over the draw¬ 
ing. Some draftsmen prefer to ink on the dull 
side of the tracing cloth; and some, on the side 
with the glossy finish. In either case, the sur¬ 
face should first be rubbed over with powdered 
chalk, in order to remove all grease from the 
surface. The chalk must then be brushed off, 
and the surface is then ready for the ink. In 


154 


MECHANICAL DRAFTING 


case the pencil drawing is made on the bond 
paper or on the tracing cloth, it may be inked 
directly, and no separate tracing is required. 

A common fault with beginners is to make 
the lines on a tracing too fine. In order to 
secure a good blue-print the lines on the tracing 
must be fairly heavy. This is also true of letters 
and numbers. 

The Blue-Print. The blue-print, which re¬ 
produces the original drawing with white lines 
on a blue ground, is obtained from the inked 
tracing or inked drawing, and is made on a sheet 
of specially prepared white paper which may be 
bought ready for use. One side of the paper is 
rendered sensitive to the light by means of a 
chemical coating. 

To make the print, the tracing or inked 
drawing is placed face up on the sensitized side 
of the prepared paper; the two are put in a 
printing frame, and exposed to the sunlight or 
a powerful electric light. The light acts on the 
prepared surface, changing it to a permanent 
blue color except where the surface is covered 
by the inked lines. The time needed for the ex¬ 
posure will vary according to the intensity of 
the light and the speed of the paper—from less 
than a minute to half an hour or more. 

After exposure, the print is taken from the 
frame, and placed in a tank of running water, 
which dissolves and washes away the parts of 
the coating that were protected by the inked 
lines above, but which has no effect on the parts 


MECHANICAL DEAFTING 


155 


that have been acted upon and fixed by the 
action of the light. The sheet is next taken from 
the tank, hung up to dry, and is then ready for 
use. 

140. Dimensioning. Dimensions are usually 
placed on a drawing so as to read from the bot¬ 
tom and from the right hand. Clearness is of 
great importance in dimensioning; and on this 
account, if for no other reason, the figures 
should be plainly made and heavy enough so as 
to stand out somewhat from the drawing. There 



Fig. 109. Correct and Incorrect 
Methods of Indicating 
Dimensions. 




*-34:'-* 

POOR 


GOOD 


Fig. 110. Good and Bad Meth¬ 
ods of Indicating Frac¬ 
tional Dimensions. 


must be no confused tangle of dimensions; 
dimension lines should not needlessly cross, and 
the dimensions must be separated enough so as 
to be clearly read. Arrow-heads are used at the 
ends of the dimension lines (with one or two ex¬ 
ceptions), to show exactly between what two 
points or lines the given dimension applies.. 

Dimensions are expressed on a drawing in 
inches, or in feet and inches, depending upon the 
distance and also on the choice of the draftsman. 
In some drafting rooms, dimensions up to two 
feet are expressed as inches; and above that, in 
feet and inches. In others, any distance over 
twelve inches is indicated in feet and inches. 












156 


MECHANICAL DBAFTING 


Where the dimension is stated in feet and 
inches, a short dash should always be placed be¬ 
tween the feet and the inches, that no mistake 
may be made in reading it. Fig. 109 shows the 
upper dimension correct, written with the dash; 
and the lower one wrong, without it. The dash 


*- 9 -» 

*-3 —^ 


<5- 4 *-» 


Tig. 111. Illustrating Use of 
Extension Lines. 




Fig. 112. Use of Extension Lines 
in Dimensioning a Circle. 

line between the arrows is the dimension line. 

Fig. 110 illustrates a good and a bad way of 
showing a fractional dimension. The line of the 
fraction should always be parallel to the dimen¬ 
sion line, never inclined. 

Extension Lines. In Fig. Ill, the short-dash 
lines extending above the figure at either end 
are extension lines. Extension lines are used 














MECHANICAL DKAFTING 


157 


for the extension of lines between which a 
dimension is to be placed, so that the dimension 
may be given outside of the figure. In this way, 
confusion is often avoided. Extension lines are 
also often used in dimensioning a circle or cir¬ 
cular piece, as shown in Fig. 112. Fig. 112 also 
shows the circle dimensioned inside. 

Where a whole circle is drawn, the diameter 
should always be given, rather than the radius; 



Fig. 114. 


Fig. 115. 


Methods of Dimensioning Arcs of Circles. 


and the dimension line should pass through the 
center. 

If, as in Fig. 113, the diameter of a rounded 
piece, as a cylinder, is given elsewhere than on 
the end view, the dimension figure should be 
followed by D or Dia. (for “Diameter”). 

Where an arc of a circle is given, indicate 
the radius instead of the diameter, as shown in 
Figs. 114 and 115. Where there is sufficient 
room, the center of the arc should be enclosed in 
a small freehand circle, and the dimension 
placed between the center and the arc as in Fig. 
115; otherwise the length of radius should be 
given as in Fig. 114, followed by the letter R to 
denote “Radius.” 










158 


MECHANICAL DRAFTING 


When an arc is given, use only one arrow¬ 
head. 

When a number of holes are equally spaced 
around a circle, give the diameter of circle pass¬ 
ing through centers, as in Fig. 116. If the holes 
are all of equal size, it is sufficient to give the 
diameter of one or two. 



Fig. 118. Half-Inch Bolt, with 
Dimensions. 


Besides the necessary dimensions of all the 
different parts of the object represented, the 
extreme outside dimensions should usually be 
given. These are known as over-all dimensions, 
and should be given so that the workman will 
not be obliged to add the several dimensions in 
order to obtain the required size. If a very long 
piece is to be shown, it may be represented as 
broken in two, and therefore drawn less in 















MECHANICAL DEAFTING 159 

length than would otherwise be necessary, the 
dimension being given as if the whole length 
were shown (see Pig. 117). 

Distribution of Dimensions. Where there 
are several views of an object on one sheet, the 
appearance will he improved and the drawing 
will be easier to read, if the dimensions are dis¬ 
tributed among the different views. In any 
case, however, where there would be likelihood 
of error, the same dimension should be placed 
on more than one view. 

Dimensioning of Bolts. For a bolt, one 
view—showing the length—is all that is re¬ 
quired. Fig. 118 shows a half-inch bolt with 
all the necessary dimensions. In addition to 
the diameter of the bolt, the thickness of the 
head, and the length under the head, there 
should also be given the length of either the 
threaded or the unthreaded portion. The num¬ 
ber of threads per inch should also be briefly 
given—as 10th, 12th, etc., as the case may be. 
For a bolt with a hexagonal or an octagonal 
head, the short diagonal is given. If the head 
of the bolt were round, D would be substituted 
for HEX; if square, SQ would be used, etc. 

141. Finished Surfaces. When metal sur¬ 
faces are to receive a smooth finish in the shop, 
the edge view of the surface is marked on the 
drawing with an italic F, as shown in Fig. 119. 
If all of the surfaces are to be finished, a note 
is made, “F all over.” 

142. Duplication of Parts. If two or more 


160 


MECHANICAL DRAFTING 


parts or pieces are to be made exactly alike, 
as bolts, pins, rods, etc., one figure is drawn and 



Pig. 119. Method of Indicating Finish for Metal Surfaces. 

dimensioned, and a note added: “Make 2 (or 
8, or 10, etc.) of this,” specifying the desired 
number. 


Sections 


143. It is often convenient, and sometimes 
necessary, to take a plane cutting through the 
object, remove one portion, and show the cut 
surface, or section. This may be necessary in 
order to give a clear idea of interior or hidden 
parts, whether the object be a small piece, or 
an office building, or a masonry structure. It 
may sometimes be inconvenient to show the 
external shape of an object by an end view; 
and in such a case a section, placed as in Fig. 
120, may be shown instead. The shape and 
proportions of a fluted column may also be well 
shown in section, as in Fig. 121. 

144. Cross-Hatching. When sections are 
made on a working drawing, it is customary to 
distinguish between the various materials rep- 
































































































MECHANICAL DRAFTING 


161 


resented, especially in the case of metals, by 
a system of one or more sets of parallel lines 
covering the sectioned surface. The surface 
treated in this way is said to be cross-hatched. 
In the matter of cross-hatching, there is no uni¬ 
versally accepted standard for all substances; 
and indeed, in some drafting rooms, the kind 
of hatching is arbitrarily chosen. 

When, on a working drawing, different ma¬ 
terials are shown in section, they should be dis- 



Hatching Sections of Ad- Fig. 121. Section of a Fluted 
joining Parts. Column. 

tinguished by cross-hatching; and somewhere 
on the sheet, there should be placed small blocks 
of the kinds of cross-hatching used, giving the 
names of the materials which they are intended 
to represent. When, in section, two adjoining 
parts are shown, the cross-hatching on the two 
parts should run in different directions, as in 
Fig. 122. 

Fig. 123 shows blocks of cross-hatching as 















169 MECHANICAL DRAFTING 

used for some of the common substances with 
which the draftsman has to deal. 

On architectural working drawings, stone 
and terra-cotta are represented in section, and 
also in plan and elevation, as shown in Fig. 124. 


p 



Wk 


’mm. 'mm. 

CAST /RON 

WRO t iron 

COPPER BRASS 



CAST S TEEL 




L. EA O BRICK MASONS Y 



TERRA COTTA CONCRETE WOOD WO Ob 

OR EIRE BRICK W/RC REINFORCE' L0N6/TUD * CROSS 

MENT. , nal SECTION SECTION 

Fig. 123. Conventional Representations of Common Materials of 
Construction. 

If, in architectural drawings, colors are used, 
they may be chosen as follows: 


Brick .Light red. 

Concrete .Payne's gray, mottled. 

Glass .New blue. 

Old work.Gray or black. 

Slate.Indigo. 

Steel and iron.Prussian blue. 

Stone .Raw umber or Payne’s gray. 































MECHANICAL DRAFTING 


163 


Terra-cotta .Burnt umber. 

Wood .Yellow ocher. 

LETTERING OF DRAWINGS 

145. The lettering on a working drawing, 
while not the most important feature, neverthe¬ 
less demands some attention. The appearance 
of an otherwise good drawing may be quite 
spoiled by poor or inappropriate lettering. The 
letter for practical use must first be legible, and 
it must admit of being rapidly and easily made. 




T.C. 

* . ‘ 




5 TONE TERRACOTTA 

Fig. 124. Conventional Representations of Stone and Terra- 
Cotta on Architectural Drawings. 

A very considerable difference exists between 
the styles of letters used in engineering and 
machine drawing practice, and those used in 
architects’ offices. 

Figs. 125 to 128 inclusive are examples of 
good, plain letters for engineering and machine 
drawing. This style of letter is known in 
machine drawing as the Gothic. The inclined 
letters are especially suitable for notes on the 
drawings. 

For architectural working drawings, a style 
of letter is used which is derived more or less 
directly from the Roman capitals. This style 
of letter, of which examples are shown in Figs. 








ABCDEFGHIJ 

KLMNOPQR 

STUVWXYZ 

1234567890 

Fig. 125. 

abcdefghijklmn 
opq rstuvwxyz 

Fig. 126. 

ABCDBrGH 
/JKLMNOBQ 
BS TU VWXYZ 
/234567390 

Fig. 127. 

obcc/efgh/jk/mn 
opqrs tuvwjcyz 

Examples of Good, Plain LmenPIuitable for Engineering and 
Machine Drawings. 

164 


MECHANICAL DRAFTING 


165 


129 and 130, admits of a freer and easier treat¬ 
ment than do those usually found on machine 
drawings. 

Spacing. Whatever the style of letter used, 
the general effect will be marred or improved 
according as the spacing is bad or good. For 
the correct spacing, no hard and fast rule can 

ABCDEFGHIJKLMN 
OPQRJ'TU V WXY Z 

Fig. 129. 

aabcdefghijklmno 


pqnstuvwxyz 


Fig. 130. 

Form of Letter Suitable for Architectural Working Drawings. 


be given; but it may be said in a general way, 
that the letters should be so placed that the 
area of the spaces between them should be about 
equal. 

The amount of time that can be devoted to 
lettering a working drawing, is in general com¬ 
paratively small; so the bulk of the lettering 
is done freehand, except on important titles for 
particular work, where some instrumental con¬ 
struction may be used. A careful study of the 
letters given in the figures, coupled with pains¬ 
taking practice, will put the beginner on the 


166 


MECHANICAL DRAFTING 


road to facility in making the various letter 
forms. 

Working Drawings for Building Construction 

146. These, as already stated, are usually 
drawn to the scale of *4 in. = 1 ft., with details 
at % in. = 1 ft., or full size. 

The number of drawings required for the 
building of a house necessarily varies somewhat 



DOUBLE SW/NG DOO& 


LAUND&V TUBS 

Fig. 131. Conventional Method of Representing Some Common 
Details of Construction on Working Drawings. 

according to its character. There should be, 
however, plans of each floor, including the roof 
and the basement or foundation plan. There 
should be also as many elevations and sections 
as may be necessary fully to explain the con¬ 
struction. Plans of the different floors, showing 
the framing, may also be required. 

Por particular details, such as cornices, win- 





































MECHANICAL DRAFTING 


167 


dow casings, balusters, mouldings, etc., it is good 
practice to draw the details at full size. Iso¬ 
metric and perspective are also often very 
helpful in the case of complicated details. 

Conventional Representations. In Fig. 131 
is shown the usual manner of representing on 
a working drawing some familiar details. 

147. Working Plans for a Residence. In 
Figs. 132 to 139 inclusive, are shown the work¬ 
ing plans for a two-family house. 

Fig. 132 is the basement or cellar plan. 
Notice the over-all dimensions, and the dimen¬ 
sion lines drawn as faint full lines. It is 
often the custom on tracings for blue-prints to 
draw construction or dimension lines with a 
narrow, full, red line. The red line prints much 
fainter than the black. Observe also the use 
of the conventional representations for the 
stonework, the windows, and the single-swing 
doors. 

In the first and second floor plans, Figs. 133 
and 134, the arrangement of the rooms is the 
same. The door between the dining room and 
pantry is one of the double-swing kind, as indi¬ 
cated on the drawing. The stairs up to the 
third floor are above the ones down to the first. 
Notice that here confusion is avoided by the 
irregular break in the stairs, and by the use of 
the arrows with the words “Up” and “Down.” 
Observe that the center lines of the windows 
are located from the walls of the house. 

In Figs. 136 to 139 inclusive are shown four 


168 


MECHANICAL DRAFTING 



Fig. 132. Example of Working Drawing—Basement Plan for a Residence. 

The scale indicated applies, of course, only to the original-sized drawing, not to the reduced 

reproduction here given. 
















































































































MECHANICAL DBAFTING 169 



Fig. 133. First-Floor Working Plan for a Residence. 



























































































































































































Dalccvny 


170 


MECHANICAL DRAFTING 



Fig. 134. Second-Floor Working Plan for a Residence. 




































































































































































































MECHANICAL DRAFTING 


171 




Fig. 135. Third-Floor Working Plan for a Residence, 




























































m 


MECHANICAL DRAFTING 



Fig. 136. Front Elevation for a Residence. 










































































































































































MECHANICAL DRAFTING 


173 



i^ig. 137. Left Side Elevation for a Residence. 






































































































































































































































































































174 


MECHANICAL DRAFTING 



Fig. 138. Bight Side Elevation for a Besidence. 


















































































































































































































































MECHANICAL DRAFTING 


175 



Fig. 139. Rear Elevation for a Residence. 








































































































































































































176 


MECHANICAL DRAFTING 


elevations. Care should be taken to compare 
the different views to see that Fig. 137 is the 
left side elevation, and Fig. 138 the elevation 
of the right side. The elevations are to show 
the distances between floors, arrangement of 
windows and sizes of glass, and in general the 
exterior finish, as shingles, siding, etc. 

For these drawings a separate roof plan was 
not required. 

STRUCTURAL DRAFTING 

148. By structural drafting is meant the 
drafting of the iron and steel framework which 
enters so largely into the construction of the 
steel bridge and the modern office or commer¬ 
cial building. 


^ r^- THICKNESS 




Fig. 140. Steel Angles with Even and Uneven Legs. 


It is impracticable within the limits of the 
present work to enter into any extended dis¬ 
cussion of the theoretical and practical ques¬ 
tions which arise in connection with this 
subject; and it is therefore the intention to 





































ILLUSTKATING EVIL EFFECT OF DISKEGAKDING BUILDING LINE. 



























































































































































































MECHANICAL DRAFTING 


177 


present only the elementary principles and 
fundamentals, with examples from actual prac¬ 
tice. Equipped with this understanding of the 
essentials, the draftsman should be able to 



I-BEAM 

Fig. 141. 



E PLAN G A 



CHANNEL 

Fig. 142. 


WCdy 


Z-BAR 


sPLANGE J 

(z 


PL.A'TEL 
Fig. 144. 


Fig. 143. 

Representations of Steel Shapes. 

readily fall into line with the practice in any 
particular drafting room. 

The various pieces which are used in steel 
building construction are largely of certain 























178 MECHANICAL DKAFTING 


standard shapes and sizes which are rolled in 
the mills. Types of the usual elementary forms 
are shown in Figs. 140 to 144. These views show 
the pieces endwise, thus representing the actual 
shape. The angles, Fig. 140, with even and un¬ 
even legs, are made in various standard sizes, 
and are listed in the handbooks issued by the 
various steel companies. 


rv—,, ,n. 


-M- Tip' 

JL JL J8L 


Fig. 145. 


Fig. 146. 


Fig. 147. 



Fig. 148. Fig. 149. Fig. 150. 

Forms of Eiveted Columns. 


Solid and Built-Up Members. The beams, 
girders, and columns may be of one piece, or 
composed of some of the elementary parts 
riveted together. Thus a beam or girder may 
be of the I-beam style, Fig. 141, in one solid 
piece; or it may be formed as in Fig. 146, of a 
plate and four angles riveted together. 

Angles (Fig. 140), channels (Fig. 142), 
Z-bars (Fig. 143), and plates (Fig. 144), are 



















MECHANICAL DRAFTING 


179, 


the elementary parts most used in the construc¬ 
tion of built-up girders and columns. The 
I-beam is commonly used as a beam or girder, 
while the uprights or columns are usually of 
the built-up variety. 

Figs. 145 to 152 show in section some of 
the common forms of riveted columns. These 


LJ 

) ( 

L. 4 

n 

) ( 

r 4 

Fig. 151. 


Fig. 152. 


Forms of Eiveted Columns. 

columns, as shown in the figures, are variously 
made up of angles, plates, channels, Z-bars, and 
lacing or lattice-work. The light lines of Figs. 
145 and 148 indicate lattice-work or lacing (see 
Figs. 153 and 154); and the heavy lines of the 
other figures are plates. Fig. 145, for example, 



is the section of a column composed of four 
angles latticed together. Fig. 147 represents 
a column formed of four angles riveted to a 
middle plate and reinforced by two other plates 
at the top and the bottom. In these figures, 















180 


MECHANICAL DRAFTING 


the narrow spaces left between the members 
which are riveted together are for the sake of 
showing the arrangement more clearly, and of 
course do not mean that such spaces exist on 
the actual column. 

Rivets and Bolts. In fastening the various 
steel shapes together, rivets or bolts are used. 
When bolts are employed, they are generally 
square-headed, with V threads, and are repre¬ 
sented in the customary manner (see “Dimen¬ 
sioning of Bolts,’’ under Article 140). 

Rivets are very largely used for fastening 
together the different members of a built-up 
beam or column, and for making connections 
with other beams. The hole for the rivet is 
made from 1 / 32 inch to 1 / 16 inch larger than the 
rivet. Rivets are driven hot, the metal being 
forced to fill the slightly larger hole. Riveting 
is done in two ways, by hand and by machine. 



Fig. 155. Machine-Driven Fig. 156. Hand-Driven Rivet. 
Rivet. 


Fig. 155 shows a machine-driven rivet; and 
Fig. 156, one driven by hand. As far as practi¬ 
cable, riveting is done in the shop, and this is 
known as shop riveting; some riveting, how¬ 
ever, must necessarily be done at the place of 
construction, and this is known as field riveting. 














MECHANICAL DRAFTING 181 

On the drawing, the rivets to be shop-driven 
are shown in position with the heads drawn; 
v/hile for those to be riveted in the field, only 
the holes are shown, blacked in. This distinc¬ 
tion is illustrated in Fig. 157, which is taken 
from a working drawing of one end of a bridge 
strut. This strut is composed of four angles 



rig. 157. Illustrating Method of Indicating Shop and Field 
Rivets. 


laced together, like the column shown in section 
in Fig. 145, two angles at the top, and two at 
the bottom. The blank circles at the ends of 
the lacing bars, and those at the ends of the 
angles, are the heads of the shop-driven rivets, 
while the black holes are for the rivets which 
are to be driven in the field. These latter rivets 
are those by which the strut is to be fastened in 
position. 

Besides the general distinction between 
shop-driven and field-driven rivets, other differ- 


I 





















182 


Fig. 158. Fig. 159. 

Conventional Methods of Indicating Kinds of Heads for Rivets—Standard of American Bridge Company. 


















MECHANICAL DRAFTING 


183 


ences are made in the drawing to denote the 
kind of rivet-head. The conventional manner 
of indicating the kind of head to be made on a 
rivet is shown in Figs. 158 and 159, which are 
according to the standard of the American 
Bridge Company. 

It will be seen that the distinguishing 
feature for field riveting is the small blackened 



Fig. 160. Rivet-Holes, Shown 
Black for Field Riveting. 


FLANGES NOT SEEN 

Fig. 162. Method of Indicating 
Flanges. 

K - 30 -3 - CES =• 12 -H 

\ ° n ^° ° ° ° °\ 

Fig. 161. Method of Indicating Equal Spacing of Rivets. 

circle, while all of the different heads for the 
shop rivets are left light. A small inner circle 
invariably stands for at least one countersunk 
head. On the side or end view of a structural 
shape, if the rivet is to be driven in the field, 
the rivet-hole is shown black, as in Fig. 160. 

When a line of rivets is to be located with 
equal spaces between, it is better to express 
the spacing as in Fig. 161, rather than to repeat 
























Fig. 163. Details of Vertical Post for Steel Bridge. 
















































































MECHANICAL DKAFIING 


185 


many times the same dimension. In case the 
total distance does not divide evenly by the 
number of spaces, the total distance may be 
given, and also the number of equal spaces 
required. 

When the side view of an angle or channel 
is shown, the flange is represented by two paral¬ 
lel lines—both full, if the flange is on the near 
side; and one or more dotted, if the back of 
the shape is shown (see Fig. 162). A similar 
practice obtains if the other shapes are shown. 

Details of a Vertical Post. Fig. 163, from a 
drawing of the Pittsburg Bridge Company, is 
the plan and elevation of a vertical post for a 
steel bridge. The post is made up of four 
angles laced together. The angles are fastened 
together at the ends by tie-plates, which, like 
the lacing bars, pass between the angles and are 
riveted to them. On the plan (the upper 
figure), the number (4) of angles used is given, 
together with the size, 3 in. by 2y 2 in. by ^4 in.; 
the symbol for angles is used, instead of the 
written word; and the total length of the angles 
is given. The hole for the 3-inch pin is located 
from each end of the pin-plates; and its distance 
from the further end of the angles is also 
shown. 

The expression “50 Alt. Spaces © 6" = 
25'-0",” lettered just above the elevation, means 
that fifty alternate spaces between rivets, each 
space equal to six inches, amounts to a total 
distance of twenty-five feet between the first 


186 MECHANICAL DRAFTING 

and last rivets of the series. The term alternate 
spaces means that each 6-inch space is the dis¬ 
tance that any rivet in one row is in advance 
of the nearest rivet in the other row. The 
distance, therefore, between any two consecu¬ 
tive rivets in the same row is 12 inches. Notice 
that the lacing bars are indicated merely by 
the center lines, and that the length as given 
is from center to center. 

This drawing illustrates actual drafting- 
room practice, such as the customary method 
of representing the angles, the manner of 
locating the rivet centers, the giving of the over¬ 
all length of the angles, and also the distinction 
between the shop- and the field-driven rivets. 
According to the drawing, all of the rivets are 
to have full heads, both sides (see Figs. 158 
and 159). 










BUNGALOW DESIGN RENDERED IN PEN AND INK 




















































































































































































Architectural Drafting 


It would be a commonplace to insist on the 
advantage to all property owners and to all 
classes of workers engaged in building construc¬ 
tion, of a knowledge of the principles of archi¬ 
tectural design. It is equally important that 
they should know how to read and interpret 
intelligently the working drawings that are the 
guides to the details of actual construction, and, 
if need be, to make these drawings themselves. 

GENERAL REQUIREMENTS 

The first impression given by a set of draw¬ 
ings applies as well in Architecture as in any 
other line of work. So often we hear it said, 
“It certainly makes a good impression.” Apply¬ 
ing this same principle to architecture, let us 
consider a few general requirements in order 
to finish a set of plans in ^he best manner, and 
also have them appeal to a person not familiar 
with architectural work. 

The drawings should be complete in every 
respect. They should be fully dimensioned 
with plain figures; all material plainly marked 
by arrows; each room named, for the sake of 
reference; and the various parts of the work 

187 



183 


ARCHITECTURAL DRAFTING 


carefully explained by explanatory notes. Make 
these notes clear, concise, and with no mistaking 
the part to which they refer. While the title 
of each page may be lettered in a more elaborate 
letter, make all explanatory notes plainly let¬ 
tered. Drawings in general have but few notes 
of explanation. Make it a rule to explain fully 
all the questionable portions of a building. 
This applies to the plans, as well as the eleva¬ 
tions, sections, and details. In the arrange¬ 
ment of notes, if there are those that do not 
refer to any particular portion of the drawing, 
place these notes over the sheet, to make it 
well balanced. Do not try to crowd them into 
one corner of the sheet or along one edge. Place 
them where they will make the drawing as a 
whole look the best. 

Architectural drawings should have some 
character to them; the lines should be firm and 
straight, making them a full, even thickness. 
Very often good drawings are spoiled by the 
lines being very poor and also too faint. Use 
a good, heavy line, and make it look as if it 
was there for a purpose. 

One way in which a drawing can be made 
attractive and “snappy,” as you will hear archi¬ 
tects say, is to overrun all corners and inter¬ 
sections of lines, slightly. In mechanical draft¬ 
ing other than the work of the architects, it is 
always required to stop the lines at the corners, 
making the drawing exact and very mechan¬ 
ical in appearance. The architect, however, is 


ARCHITECTURAL DRAFTING 


189 



Tig. 1. Part Plan, Showing Method of Overrunning Comers. 












































190 ARCHITECTURAL DRAFTING 

allowed some liberties in his work. He will 
resort to methods, to improve the looks of his 
drawings, which would not be permissible in 
other work. 

Referring to Fig. 1, it will be seen that the 
corners and intersections are emphasized by the 
overrunning of the lines. This does not mean 
long lines past the corners, but just enough to 
show a sharp intersection. A little practice will 
soon enable a draftsman to do this work skil¬ 
fully, and once this method is adopted it will 
be used on all future work, as there is no com¬ 
parison in the general attractive appearance of 
two drawings, in one of which this method is 
used, and in the other the strict mechanical 
method is adhered to. The actual time con¬ 
sumed in getting out a drawing is less with the 
method described than with the true mechan¬ 
ical drawing, in which it is necessary to start 
and stop at exactly a certain point. In mechan¬ 
ical drawing, it is frequently necessary, after 
two lines at an angle have been drawn, to go 
over the first line in order to continue it a short 
distance to the exact corner. 

Very often, a few minutes spent on careful 
lettering, indicating materials, and an additional 
explanatory note, will be the winning feature 
of a set of drawings. 

Too much emphasis cannot be placed upon 
always being on time, whether in office work 
or in getting out drawings. When a time is 
set for the completion of any drawing, or a time 


ARCHITECTURAL DRAFTING 


191 


of meeting arranged, have your work ready at 
that time, and keep your appointment exactly 
as arranged. Before setting a time of comple¬ 
tion, be sure you are giving yourself time to 
do the work completely, and then see to it that 
your work is ready at that time. 

The architect’s services usually consist in 
preparing the necessary studies or preliminary 
sketches, working drawings, specifications, and 
large-scale and full-size details, together with 
a general supervision of the work. For this 
service, there is usually a price based upon a 
minimum percentage of the completed work. 
This percentage varies in different States and 
localities, from 3 y 2 to 7 per cent. As the work 
progresses, or different sets of drawings are 
completed, payments are made. If we consider 
the architect receiving five per cent commission, 
one-fifth the entire fee is due upon the com¬ 
pletion of the preliminary sketches, two-fifths 
upon the completion of the working drawings 
and specifications, the balance being paid as the 
work progresses. This percentage is based on 
the total cost of the buildings. These prices are 
those adopted by the Chicago Architects’ Busi¬ 
ness Association. Should work on the drawings 
be abandoned, a charge should be made for 
services for the amount of work done. 

This will give an idea as to the general 
prices charged, and the usual times of payment. 
It does not pay to do work at a small percent¬ 
age, for the work on the drawings and specifi- 


192 ARCHITECTURAL DRAFTING 

cations will necessarily have to be inferior and 
incomplete. 

The scales at which drawings are usually 
made are % in., y± in., y 2 in., % in., % in., iy 2 
in., and 3 in., to the foot. These are convenient 
for all parties concerned. We see that by using 
the first three scales we can use the regular 
divisions on a rule, without having an architect’s 
scale. The last scales are also convenient for 
the same reason. Take, for instance, a detail 
drawn at 3-inch scale; then we see that y± inch 
equals one inch, and an ordinary rule can be 
used to advantage. On the actual construction 
work, the foreman always uses his two-foot rule 
for scaling the drawings; and if the above scales 
are used, they are easily read from an ordinary 
rule. 

A complete set of drawings should include a 
survey, or City Engineer’s plan, of the lot, on 
which the outline of the building is marked; a 
foundation plan; a plan for each floor; a roof 
plan; an elevation of each side of the house; 
all necessary %-inch scale detail sections; all 
necessary elevations of interior finish; large- 
scale details of the window-frames and sash and 
interior trim; and any other details of unusual 
construction. After the contract is let, then 
get out full-sized details. 

Should any changes be necessary after the 
drawings are completed, secure the owner’s 
written order for such changes. If everything 


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ARCHITECTURAL DRAFTING 193 

is in writing, there can be no cause for dispute, 
especially in the matter of changes. 

METHOD OF GETTING OUT DRAWINGS 

The prospective client, by appointment or 
otherwise, meets the architect in his office. The 
general scheme is talked over, and the various 
subjects are discussed, such as the lot, location, 
size, etc.; the amount to be put into the build¬ 
ing, or the cost; the time of beginning and 
completion; the owner’s general idea of the 
requirements; and the architect’s fee. A time 
is set for the getting-out of the preliminary 
sketches. All of this information is arranged, 
and entered in a book for future reference. 

At the appointed time, the client appears 
again, and the preliminary sketches are talked 
over, changed, and revised, and any new infor¬ 
mation is noted. After another visit or two 
by the client, the sketches are accepted. The 
working drawings are begun, usually made at 
%-ineh or 1,4-inch scale. These drawings are 
carefully inspected by the head draftsman, num¬ 
bered, dated, and signed. 

These drawings are then reproduced by some 
method—usually blue-printed—bound, and sent 
to the contractors for bids or proposals on the 
work. After the contract has been let, the full- 
sized drawings are made. 


194 ARCHITECTURAL DRAFTING 

AECHITECTUEAL DEAWINGS 

Architectural drawings may be classified as 
follows: 


_ . fSketches 

Preliminary Perspective sketches 

Drawings [competition Drawings 


Working 

Drawings 


General 

Detail 


Scale Details 
Full-Size Details 


Preliminary Drawings 

Preliminary drawings are small studies of 
the proposed new work, freehand or otherwise, 
at a small scale, finished in an attractive man¬ 
ner. There are three classes of preliminary 
drawings—namely, Sketches, Perspectives, and 
Competitive Sketches. 

Preliminary Sketches. In architectural work, 
no matter whether you are an architect dealing 
with an owner or client, or a draftsman getting 
out working drawings, it is always better to 
make a preliminary sketch of the arrangement, 
detail, etc., as it saves time and much erasing 
and changing on the scale drawings. By pre¬ 
liminary sketches we mean the sketching free¬ 
hand on paper to show exactly just how you 
will draw it with the T-square and triangles. 

Let us consider the architect dealing with a 
client. The first thing is an arrangement of the 



ARCHITECTURAL DRAFTING 195 

rooms, or the plan is first studied. For this 
work, tracing paper will be found very easy to 
work with and very convenient. The use of a 
sheet of co-ordinate paper under the tracing 
paper will be found very convenient. The 
squares on the co-ordinate paper will serve as a 
guide in drawing straight lines; and also the 
squares as ruled on this paper can be used as 
a scale—one square representing one unit, as a 
foot or an inch. 

Very often the owner of the proposed new 
building will have some scheme or arrangement 
of rooms that he would like; therefore, try to 
have him give you a rough sketch of such 
arrangement; even a drawing with single lines 
for walls, and cross-lines indicating windows, 
will be very helpful. A drawing as shown in 
Fig. 2 is just what you want from your client. 

Having received either this sketch or a list 
of the requirements, you are ready to start your 
preliminary sketches. Spread down the co-ordi¬ 
nate paper, and over this lay a sheet of tracing 
paper. These may be held down with thumb¬ 
tacks or weights of some sort placed on opposite 
ends. Assume each square of the paper to 
represent some unit, as one inch, or one foot, or 
ten feet; and lay out first the property lines. 
Then commence on the building proper. Make 
no attempt at trying to make exact lines; let 
these sketches be more of freehand drawing. 
Mark off the approximate sizes of rooms by 
rectangles, and try the various arrangements, 


196 


ARCHITECTURAL DRAFTING 







































ARCHITECTURAL DRAFTING 197 

endeavoring to secure an ideal arrangement. 
Make no attempt at trying to show double lines 
for wall lines; let it be a free and easy sketch 
of single lines. 

Don’t be satisfied with one arrangement of 
the given requirements. Over this first sketch 
lay another sheet of tracing paper. Perhaps 
you can use some parts of the first sketch, and 
revise other parts. Study your problem, and 
be fully acquainted with the requirements. 
After completing this second arrangement, try 
to imagine difficulties that this arrangement 
would present, and how they might be remedied. 
Make another sketch; don’t be satisfied until you 
have made half a dozen different sketches. 
After having considered all the possible arrange¬ 
ments of the requirements, then take the 
sketches, spread them all out before you, and 
see if you have solved the problem. 

Now commence with a clean sheet of tracing 
paper over the co-ordinate paper, and make fin¬ 
ished sketches; that is, lay out the wall lines 
carefully, put in the windows and doors, letter 
the rooms, and get these drawings into shape to 
submit them to the client. Make them so that 
he will understand clearly the arrangement you 
have sketched. 

For filling in the walls to indicate the walls 
and the windows, it will help the appearance 
to color the walls on the back side of the paper 
with the pencil. This gives a subdued color to 


198 AKCHITECTURAL DKAFTING 

the walls, and increases the clearness of the plan 
or drawing. 

Prepare small sketches of possible treatment 
of the elevations, and submit these also with 
the plan. These will now do for you to submit 
to your client (see Fig. 3). Be very sure that 
you have studied the problem thoroughly, and 
be prepared to answer all questions your client 
will probably ask. The client will very soon 
form an opinion of your ability by the way 
you handle his work. 

When these first preliminary sketches are 
ready, notify your client, unless you have had a 
previous time of meeting set. If this be the 
case, then be sure to have your work ready for 
him at the appointed time. Remember, your 
client is a busy business man, a man who is 
always used to keeping his appointments, and 
expects everyone to keep theirs. 

After these first sketches have been sub¬ 
mitted, and carefully gone over, make an ap¬ 
pointment for the next meeting, at which time 
you will have the final preliminary sketches 
ready. There will always be changes and addi¬ 
tions on these sketches; and the fewer times 
the client has to be consulted, the better im¬ 
pression you will make. Therefore, after this 
first meeting, understand thoroughly your 
client’s objections and changes, ask questions 
to make sure you do understand, and go back 
to your office determined to make the revisions 


ARCHITECTURAL DRAFTING 


199 



Fig. 3. First Sketch Ready to Submit to Owner. 

Original drawn at scale of = l'-O", all freehand and drawn on 
co-ordinate paper. 



















































200 ARCHITECTURAL DRAFTING 

and that the next sketches submitted will be 
approved. 

For the next sketches, it is very often more 
satisfactory to use the T-square and triangles, 
and a scale, and make small, sketchy drawings. 
Tack down your tracing paper, and lay out to 
a small scale the general arrangement (Fig. 4). 
Every little detail need not be attempted on 
these sketches; but make them straight-line 
drawings, using more care in the finishing of 
such drawings. Make all plans necessary, show¬ 
ing the arrangement on all floors; also an eleva¬ 
tion. Make them attractive, and letter com¬ 
pletely. 

The next meeting with your client should be 
the last one so far as the sketches are concerned. 
Have him look over all your sketches closely; 
go over them with him, pointing out the changes, 
telling him the advantages to be gained by this 
or that arrangement, and convince him that you 
know your business. He will finally see things 
your way, and he will tell you to go ahead with 
the work. If you see he is satisfied with the 
arrangement as shown him on the sketches, 
secure if possible his initials of approval (in 
ink) on each sheet. Don’t ask him to “sign 
these sketches,” as if you were an owner and 
he a lease-holder. If there is anything a busi¬ 
ness man hesitates to do, it is to sign his name 
to a paper of any kind. Use a little tact, tell 
him that you want him to be perfectly satisfied; 
and in order for him to be sure he is going to 


ARCHITECTURAL DRAFTING 


201 

















































































202 


ARCHITECTURAL DRAFTING 


get the arrangement that suited him, he can 
0. K. the sketches that he approves, and thereby 
have a check on the working drawings so that 
they will be sure to be what he wants. On the 
other hand, you are protecting yourself by this 
signature. Very often your client may forget 
that he ordered this or that change in your 
sketches; he might in some cases refuse to pay 
you your agreed commission, because you did 
not do this or that thing which he ordered. If 
you have his signature on the sketches, and 
you have followed these sketches exactly, you 
will not fear the outcome should the case go to 
law for settlement. 

The same general method of procedure will 
apply if you are a draftsman getting out scale 
details. Get out freehand sketches on tracing 
paper, several of them; decide which is the best 
method before making the regular scale details. 
If you are a new man in an office, submit your 
best sketch for the construction to the head 
draftsman, and let him see that you are studying 
your work, endeavoring to get the best method. 
Learn to make your sketches clear and well 
executed. This comes only by practice in 
sketching. 

Much time and money can be saved on the 
cost of getting out the drawings if only you 
learn to make these sketches well and complete, 
so that when you are ready to make the final 
drawings, you can start and know definitely just 
what they will include. 


ARCHITECTURAL DRAFTING 203 

It will be found very convenient to use a 
soft pencil. Never use a hard pencil on your 
drawings, no matter whether they are the 
sketches or scale drawings. 

It is very necessary for a draftsman to know 
how to make preliminary sketches. Very often 
a new draftsman’s ability along architectural 
lines is tested by these preliminary sketches, 
their make-up, the method of getting them out, 
and the time taken to get them ready. If a firm 
finds out that you can make attractive and yet 
practical preliminary sketches, you will soon 
find out that you will not be required to serve 
your time at tracing drawings or details, as most 
draftsmen have to do upon entering a new office. 

Perspective Sketches. A perspective is a 
representation of a building or object as it ap¬ 
pears from a fixed point. These sketches are usu¬ 
ally drawn at a small scale, either freehand or 
mechanically. The lines should be lightly drawn 
or sketched, as strong lines will be objection¬ 
able in the rendering or coloring of the drawing. 
The rendering may be in pencil, ink, water- 
color, or sometimes in crayon, and prepared 
upon almost any kind of paper (see Fig. 5). 

Competition Drawings. These are more or 
less preliminary sketches. As a general thing 
it is only occasionally that a firm enters a com¬ 
petition; but if it should, let the draftsman show 
that he knows how to prepare such drawings. 
By competition drawings, we mean drawings 
that are submitted in a competition. The firms 


204 


ARCHITECTURAL DRAFTING 


may be invited to submit competition designs, 
in which case it is called a closed competition; 
or the requirements may be published in some 



Fig. 5. A Freehand Perspective Sketch. 

architectural paper, and anyone may submit 
drawings, in which case it is called an open 
competition. The drawings submitted for the 
open competition are more of the nature of 
sketches than in the closed competition. Usu¬ 
ally, in the closed competition, each firm invited 
to submit drawings will be paid for their work 
even though unsuccessful in being the winner. 
There is generally a sum paid for such drawings. 
Thus, in a closed competition, an architect is 
paid for his time and can afford to get out a 
better class of drawings. These are usually 
drawn on regular drawing paper, carefully laid 
out to scale, and all inked in. The sheet is then 
water-colored and made as attractive as possible 


















ARCHITECTURAL DRAFTING 205 

in this manner. In other words, these drawings 
are laid out as carefully, except at a much 
smaller scale, as working drawings; only the 
important dimensions are put on. 

In the open competition, the work is usually 
done on tracing paper. The plans are laid out 
at a small scale, made very sketchy, and the 
pencil is allowed much freedom in the lines. 
With this sort of drawing, it is necessary to 
study the requirements, make sketches, and 
decide for yourself which answers the require¬ 
ments the best. There will be no client to criti¬ 
cise your work, but you will have to do this for 
yourself and submit your sketches as final 
sketches to the client. The first-floor plan is 
laid out, and the surrounding premises are also 
laid out. Trees and shrubbery also are put on; 
and walks, drives, and gardens are shown. Since 
this is on tracing paper, very little water-color 
is used. Use the pencil to show everything, 
and upon your ability to use your pencil—and 
a soft one, too—will depend much of the success 
of your drawings. After these sketches have 
been made, they are lettered and titled attrac¬ 
tively, and then mounted on cardboard. This 
mounting is usually done by pasting the corners 
only, and not attempting to paste the whole 
drawing. Ordinarily, a border of some sort is 
placed around the card, and any other finishing 
touches that will make the drawing attract 
attention are added. Thus we see that competi- 


206 ARCHITECTURAL DRAFTING 

tion drawings are only preliminary sketches 
finished a little better than for the ordinary class 
of work. 

Should you be successful in the competition, 
the method of getting out the working drawings, 
scale details, and other drawings, is the same 
as for any other work. 

The chances are that you will rarely have a 
chance to get out competition drawings; but 
should the opportunity come, grasp it, and do 
your best. 

Working Drawings 

By working drawings we mean drawings 
complete in every respect, with dimensions, 
sizes of rooms, etc. In other words, they are 
the drawings giving all the necessary informa¬ 
tion to completely build the structure as drawn. 
This division of drawings may be divided into 
general and detail drawings, the latter being 
subdivided into scale and full-size. 

The architect who is mindful of his client’s 
welfare will furnish a complete set of drawings. 
The clearest, simplest, and most exact working 
drawing is the best. Some architects feel that 
working drawings do not require the best work. 
The making of good, clear, complete drawings 
cannot be emphasized too strongly. 

The Plan. In the plan we see an arrange¬ 
ment of the rooms for the different floors that 
approaches the ideal as nearly as possible. The 
plan should present the conveniences of arrange- 


ARCHITECTURAL DRAFTING 


207 


ment. In the following description we shall 
consider the plan of a residence, as it will clearly 
set forth the logical arrangement of parts. The 
description, as noted, will be limited to residence 
work, since this class of building is likely to 
afford a student his first opportunity for inde¬ 
pendent, original work. 

The same reasoning could be extended and 
applied to any class of building. Usually the 
first-floor plan is worked out first, as it is the 
most important, since the greater part of the 
day is spent in this portion of the house. The 
upper floors, being used almost entirely for bed¬ 
rooms or minor rooms, can be worked out to 
conform to the outline of the first-floor plan. 
The basement usually is devoted to the heating 
apparatus and its accessories, the laundry, store¬ 
rooms, and such. Therefore, the first-floor plan 
will govern the outline of the basement walls; 
and the basement rooms will be arranged inside 
the basement walls, as determined by the first- 
floor plan. 

In residence work we see two classifica¬ 
tions—the city house and the country house. 
The city house gets its sunlight from the front 
and rear, being usually built in between adjacent 
houses where there is no chance of sunlight from 
the sides. A country house gets its light from 
all four sides; that is, it is built in a part of 
town where the lots are of sufficient width to 
give plenty of light and air. The city house 


208 ARCHITECTURAL DRAFTING 

usually has a lot 20 to 30 feet wide, and it is 
a question of the best arrangement for light as 
well as comfort. The country house usually 
has a lot 50 to 60 feet wide; and it is not un¬ 
common to see a house built on two lots, giving 
all the more room. 

Let us, therefore, consider the first-floor plan. 
Upon entering a residence, we usually step into 
a vestibule. This room, while small and inferior, 
yet is one of the most important rooms in the 
house. The vestibule should be well lighted, 
which can be done by means of glass in the 
front door, by side lights along the sides of the 
door, by a transom, and by glass in the door 
leading into the living room. The vestibule 
should be provided if possible with a closet (it 
need not be large), in which a person’s every¬ 
day hats and wraps may be kept, also all rub¬ 
bers and umbrellas. It is very evident that 
this will be the first need upon entering a home— 
a place to dispose of one’s coat, hat, etc., before 
entering the home proper. It is all the more 
urgent in a mild, rainy climate. In case a closet 
cannot be provided, there should be a seat with 
a hinged cover, and a stand for umbrellas, with 
the usual furniture for holding the coats and 
hats. This room, as already said, need not be 
large, as usually not more than two people are 
ever in the room at the same time. In some 
residences there is no vestibule, but it is almost 
a necessity in the best class of work. 






















































































. 

* 







DESIGN FOE A CARRIAGE SHELTER. 













































































































































































































































































































ARCHITECTURAL DRAFTING 


209 


From the vestibule, we now come to the 
reception room. This room is usually large, with 
but little furniture. The main stairway leads 
up from one side of this room and is made quite 
ornamental. The other side is usually open, 
or separated by columns or grill-work from the 
living room. At one end of the reception room, 
one frequently sees a fireplace, more or less 
elaborate. 

Turning now to the living room, let us study 
the requirements of this room. Here is the 
room the family will spend most of the time in. 
Often one end is set apart for a nook or library. 
There should be a large open room with a fire¬ 
place of brick or stone or tile or other suitable 
material, ornamental or plain, or the mantel may 
be of wood. 

Provide plenty of windows, especially on the 
sunny side of the house. Nothing will dispel 
gloomy feelings or worry quicker than plenty 
of sunlight and fresh air. For the nook, if there 
is one, build in shelves for books, put in a seat 
with a hinged cover, also a fireplace. In this 
room, the quiet hours of the day are spent; 
therefore make it comfortable and convenient. 
A very convenient arrangement is to place a 
seat on one side, with bookshelves on the other; 
also a few shelves at one end or above the seat, 
for current books or periodicals. Provide a 
plate-rail around this nook, for the placing of 
china, ornaments, or bric-a-brac. 

Opening from the living room we usually 


210 


ARCHITECTURAL DRAFTING 


find the dining room, separated by sliding doom 
This room should be more or less private, but 
by means of double doors it may be thrown 
open when desired. In the dining room, build 
in a sideboard, and provide a small shelf or two 
for pretty china, vases, or ornaments. Back of 
these shelves a mirror is usually set. A French 
beveled-plate mirror is used in the best work. 
There should be the “ counter, ” or the main 
shelf, projecting from two to six inches beyond 
the shelves and drawers below. Below the 
counter, provide a long drawer that will take 
a table-cloth as folded when laundered. A 
drawer for silver is also directly under the 
counter. Below this, there may be either 
drawers for other table linen, or shelves enclosed 
by glass doors for displaying china or cut glass. 
This sideboard should be made an attractive 
feature of the room. There might also be an¬ 
other case of shelves and drawers for additional 
table linen and dishes. There should be a plate- 
rail around the room, on which to hang cups or 
to place china or ornaments. This room should 
have, if possible, an east exposure, since the 
first meal of the day should be served in a bright, 
cheery atmosphere. 

It will be necessary to have a serving pantry 
between the dining room and kitchen. There 
should be double-acting doors. This greatly 
facilitates the carrying of dishes from one room 
to another. In this pantry should be a wide 
shelf or counter which will be used in the prep- 


ARCHITECTURAL DRAFTING 


211 


aration of the meal. Above are shelves with 
sliding doors, and below are drawers for differ¬ 
ent articles of food. Provide always plenty of 
drawers and shelf room. In a small room, 
sliding doors will be found much more con¬ 
venient than swing doors, as they are much more 
easily handled and take up much less room in 
opening and closing. If possible, there should 
be built in this room a refrigerator. If not here, 
place it in the kitchen. This refrigerator should 
be provided with an outside door through which 
the ice may be replenished from the outside, 
thereby doing away with the ice man coming in 
at all hours and in bad weather tracking mud 
into the house. 

The kitchen, while in the rear of the house, 
requires careful thought. The housekeeper 
usually spends the greater part of the morning 
here; therefore give this room, if possible, an 
east exposure. Make the windows low enough 
so that a person sitting can see out. For the 
kitchen table and sink, have a window near. 
This will not only be an aid to better light, but 
will give the housekeeper a chance to see out 
through the window. Place a sink as near the 
pantry and dining room as possible; also, as 
mentioned above, so as to be near outside light. 
In the kitchen will be found a cooking range or 
gas stove, or both. Place these, if possible, 
where they will get a cross-draft; in other 
words, place them between a door and a window, 
or between windows, so that the odor during 


212 ARCHITECTURAL DRAFTING 

the preparation of a meal will be carried away. 
Of course there is necessary a flue for the range, 
and there should also be one for the gas stove 
to carry off the odors of the gas and the ovens. 
The kitchen table should be convenient to the 
stoves. There should be built-in shelves and 
cupboards for the kitchen-ware and the pots and 
kettles. Either in the serving pantry of some¬ 
where in the kitchen, provide a tilting bin for 
the flour. This can be very easily done by 
making the bin pivoted at the outside corners, to 
allow the bin to tilt out. Hooks or pivots for 
swinging a barrel of sugar would also be a great 
convenience. Ho not make the kitchen large; 
make it small, compact, and convenient, to save 
the housekeeper all unnecessary steps. There 
will also be necessary rear staii’s, one to the 
basement and one to the attic. These stairs 
should be about 3 feet 6 inches wide, as boxes, 
furniture, etc., are all taken up or down these 
stairs; so do not make them too small. 

Having decided upon a satisfactory arrange¬ 
ment of the lower floor, we now consider the 
upper floors. These are devoted to the bed¬ 
rooms and other rooms where more privacy is 
desired, such as the sewing room, the study, or 
the nursery. As has been said, the first-floor 
plan determines the outline of the second-floor 
plan. The number of bedrooms is determined by 
the size of the family. There will be required 
also a guest room and a servant’s room. 

As to the requirements of a bedroom, make 


ARCHITECTURAL DRAFTING 


213 


ample-sized rooms. The usual articles of furni¬ 
ture will be the bed, a dresser, a chiffonier, a 
small table, and sometimes a writing desk or 
an additional table of some sort. Provide plenty 
of closet room, with a window, if possible, in it. 
In the closet should be a number of shelves, a 
hook strip around the three sides. The closet 
should be finished, so far as plaster and inside 
finish are concerned, as well as the other rooms. 
The question of closets is important; therefore, 
consider them an essential part of every house. 

On the second floor provide a bathroom con¬ 
venient to all rooms, yet far enough away from 
the main hall to be private. The bathroom is 
usually crowded into any remaining space that 
may be left after bedrooms have been consid- 



ic 


i 


Fig. 6. Layout of a Very Small Bathroom. 


ered. This, however, is not a satisfactory way 
of doing, since the bathroom should be as con¬ 
venient in arrangement as any other room. In 
the bathroom the usual necessary fixtures are 
a bathtub, a lavatory or wash-bowl, and a water- 
closet. In more expensive homes a foot-bath 
and a sitz bath are provided; sometimes a 
shower bath also. There should be ample room 
for the placing of these fixtures, with plenty of 














214 


ARCHITECTURAL DRAFTING 


room around them. In Fig. 6 is shown the 
smallest room that can accommodate the neces¬ 
sary fixtures. While this will serve in the 
cheapest houses, yet the arrangements shown in 
Figs. 7 and 8 are much better. 

Should more fixtures be added, the room 



Tig. 7. 


Fig. 8. 


Two Plans of Commodious Bathrooms. 


should also be made larger to accommodate 
them. There will also be required a medicine 
chest, usually built into the wall directly above 
the lavatory, or these can be bought at furniture 
stores, ready to hang on the wall. There should 
always be a mirror in the door of this chest. 
Provide a built-in closet with swing doors for 
the upper half and drawers for the lower half. 
The finish of this room, as well as the shape of 
the mouldings, should be such that the dust will 
not easily settle on them, and that they may be 
frequently washed to remove any accumulation 
of dust. 

In most homes, the two main floors are all 
that are required for living rooms. The attic 
is usually low, and can be fitted up with store- 
















ARCHITECTURAL DRAFTING 


215 


rooms. The construction of the roof should be 
such that soot and dirt cannot come through. 
This is ordinarily accomplished by using build¬ 
ing paper under the shingles or roof covering. 
There should be an attic stairs, convenient and 
easy of ascent. 

For the basement, the furnace will require a 
part of the space, together with a coal room. 
This coal room should be built dust-tight, and 
have a window convenient to a driveway for 
the unloading of coal. The size of coal room for 
different classes of coal, is indicated below under 
the heading “Dimensions.’’ There should be a 
laundry with laundry tubs, or a room where the 
family washing may be done. The remaining 
space in the basement may be divided to suit 
the owner’s wishes; sometimes a work-room, a 
store-room, a drying room, a shop, may be placed 
here. 

It is very essential to have a concrete floor 
over the entire basement. This will do away 
with a great deal of dirt and dust that otherwise 
would be carried from the basement all over the 
house. There should be an outside entrance, 
as well as an entrance from the kitchen or 
serving room. 

Thus we see the usual requirements for the 
different rooms of the house. The essential 
rooms have been considered. In addition to 
these, if the price will warrant it, there may be 
other rooms and conveniences, such as a den 
or study, additional store-rooms, an extra guest 


216 


ARCHITECTURAL DRAFTING 


room, a nursery, a pantry off the kitchen for 
storing the supplies of the kitchen. A clothes- 
chute would be very convenient also. This chute 
is a vertical shaft connecting the bathroom with 
the laundry in the basement. There is a door 
into this chute at the bathroom, and one on the 
first floor. It should be lined with wood, with 
the pieces placed vertically to offer no obstruc¬ 
tions to the passage of clothes. The purpose is 
evident, being a means of conveying the soiled 
linen from the second and first floors to the base¬ 
ment, and thereby saving carrying them from 
all over the house in a basket to the basement. 

In summing up this portion of the work, let 
the draftsman put in all conveniences in the way 
of cupboards, shelves, and drawers wherever 
there is a space, corner, or portion of a wall. In 
this way you make a favorable impression upon 
the housekeeper, and if this is done, the “ battle 
is more than half won.” 

Fig. 9 is a first-floor plan, showing the 
arrangement, the dimensions, and all necessary 
information to give the builder a complete 
understanding of the work. 

The Elevation. Having considered briefly 
the general methods used in the drawing of 
architectural plans, we shall now consider the 
elevations. By elevations we mean the different 
“views” of the building. These should show 
exactly the appearance of the building when 
completed. 

Use of the Orders. It will be assumed that 


ARCHITECTURAL DRAFTING 217 

the reader is familiar with the Orders of Archi¬ 
tecture (see below under heading “Orders of 
Architecture”), and that he knows the names 
of the various parts of an Order. 

From a study of the Orders, we see that each 
one has three main divisions, the entablature, 
the column, and the pedestal. These are in turn 
divided into parts, the entablature consisting of 
the cornice, the frieze, and the architrave; the 
column has a capital, a shaft, and a base or 
plinth; and the pedestal, a cap, a die, and a base. 
Generally speaking, an elevation—especially the 
principal one—shows these component parts of 
an Order. They may not be classically correct in 
proportions, but the parts are more or less 
prominent, and should be used as a basis for 
design of all classes of work. 

Let us take a residence for an example. 
Study an elevation of a good type of this class 
of building. We see that the basement wall up 
to the first-floor line corresponds to the pedestal 
of the column, a strong, massive part to support 
the building above. This pedestal is usually 
capped by a projecting course we call a water- 
table —that is, a board or strip projecting from 
the face of a wall to turn the water from the 
side of the building away from the foundation. 
This corresponds to the base or plinth of the 
column. Above the water-table, the part of the 
house extending to above the top story windows 
corresponds to the shaft of the colmnn. Very 
often this column effect is emphasized by means 


218 ARCHITECTURAL DRAFTING 



Fig. 9. First-Floor Plan of a Eesldence at Champaign, Ill. 

The scale reproduced is valid only as referring to the original-sized 

drawing, 





















































































































































ARCHITECTURAL DRAFTING 


219 


of corner boards at the corners of the building. 
At the head of the top windows, or in that vicin¬ 
ity, we see a horizontal board or moulding, mark¬ 
ing the division between the column and the en¬ 
tablature. Sometimes this entablature is divided 
by another moulded course, indicating the 
frieze and the architrave. There is always a cor¬ 
nice of some sort, very often corresponding to 
the cornice of the Order; this may vary from the 
true profile to a small projection, such as a few 
projecting courses of brick. 

In the modern office building we see the lower 
stories marked by a projecting stone course; 
below this, the walls are of stone, and usually 
present a solid, substantial base upon which rests 
the upper part of the building. The column is in¬ 
dicated either by pilasters or column-like projec¬ 
tions from the main face of the building, or by a 
three-quarter column fastened to the building. 
The upper stories, depending upon the height of 
the building, are placed in the entablature. 

It is worth while to study this feature in all 
classes of building, in order to design intelli¬ 
gently. 

Thus we see that the Orders of Architecture 
are really the basis for all our designs. This same 
applies to any type of building, being more 
marked in some classes of buildings than others. 
The Colonial residence or Colonial Architecture 
adheres strictly to this basis of ornament. If de¬ 
tached or free columns are used for porch con¬ 
struction, then we see the component parts of 


220 


ARCHITECTURAL DRAFTING 


the Order carried out exactly. Therefore, in any 
building, use the Order to start the general ele¬ 
vations, and elaborate or suit the elevation to the 
class of building. 

Characteristics of Types of Buildings 

Let us now consider the general types of 
buildings for different purposes. The residence, 
for instance, usually has the appearance of a 
quiet, restful place. The types of doors, win¬ 
dows, and roof lines are in general similar, there 
being large windows and plenty of them. Resi¬ 
dences thus constitute a class marked by well- 
known and easily distinguishable general char¬ 
acteristics. 

Consider a library. We see here a closer ad¬ 
herence to the Orders than in many other types 
of structure. Usually there is a jhllared entrance 
of some form or other; the windows are all large 
and dignified. The roof is covered with tile or 
some other more expensive covering. In general, 
libraries are a dignified class of buildings, easily 
distinguished as such, and usually quite costly. 

In schoolhouses we see a class of buildings 
with large areas devoted to windows, not usually 
of very great height, and with a tower of some 
outline. There may be large, blank walls, which 
make this class of buildings all the more distinct. 

The office building generally has numerous 
windows, not usually grouped but placed one 
above the other, and is rather plain in treatment 
except at the cornice. 


ARCHITECTURAL DRAFTING 


221 


The warehouse forms another excellent ex¬ 
ample of the exterior indicating the purpose of 
the building. In this type, we see small windows, 
some barred, with heavy doors, showing it to be 
a building of great strength and fire-resistance. 

Thus endeavor, in designing any building, to 
make it indicative of the purpose for which it is 
designed. Study carefully from examples or 
from pictures these characteristics, and apply 
these principles to designs you may submit. 

General Composition of a Building or Treat¬ 
ment of Elevations. A few words about the gen¬ 
eral composition or elevation of a building might 
be said. There are a few principles involved 
that will be an aid in deciding upon the charac¬ 
ter of the elevation. 




Fig. 10. Illustrating Method of Treating Elevations. 

In A, vertical lines are emphasized, adding to the appearance of 
height; in B, emphasis is laid on the horizontal lines, 
adding to breadth and length of structure. 

The adjoining buildings will sometimes have 
a certain influence upon the treatment of the 
elevation. Should the new building be placed 
between two buildings taller and larger in every 
way, then some means to increase the general 
height must he used. Should there he plenty of 
room and the buildings on either side be far 






















222 ARCHITECTURAL DRAFTING 

enough away so that they will not be seen or in¬ 
cluded in the general view of the new building, 
then the design may be anything in keeping with 
good design. If the present buildings are large 
and massive, covering a good deal of ground, 
then we shall treat the new elevation correspond¬ 
ingly. In Fig. 10 are shown the results, on the 
same building, of different treatments of eleva¬ 
tion. In A we see vertical lines emphasized, as 
they tend to increase the height. Such a treat¬ 
ment of the elevation should be used if the loca¬ 
tion were between two taller buildings. In B on 
the other hand, the horizontal lines are empha¬ 
sized. There is the sill course or water-table at 



A B 


Fig. 11. Two Typical Methods of Treating Windows. 

the first-floor line; then a belt course about the 
second-floor line, and a course at the attic line. 
These tend to lengthen the general appearance, 
and would be in keeping as mentioned above for 
the third condition. In A, we see that the cor¬ 
nice is made smaller; while in B, the eaves are 













































ARCHITECTURAL DRAFTING 


223 


given a greater projection, thereby giving an¬ 
other horizontal line. A and B are exactly the 
same size in plan and also in height to the eave 
line; yet there is no mistaking which appears the 
taller. 

This is the fundamental principle in the de¬ 
sign of an elevation. Having then this start for 
the elevation, carry out the same principle in the 
windows, either grouping them and keeping 
them low, for the design B; or else use single 
windows with a pier or wall space between. Very 
often, if the ceilings are high enough, windows 
may have a transom bar and transom, thereby 
increasing the height. In the treatment around 
the windows, for B, we shall use merely a cap of 
some kind with no vertical lines; while for A we 
shall make use of an outside trim with a cap. 
See Fig. 11. 

In all our designs, it has been attempted to 
emphasize either the vertical lines or the hori¬ 
zontal lines. This is but one—the most impor¬ 
tant one, however—of the points to consider as 
to the general character of the elevation. The 
purpose of the elevation is to give an effect that 
will be pleasing to the eye, and at the same time 
fulfil the requirements of the plan as to the ar¬ 
rangement of windows and story heights; and 
very often it will make the property more valu¬ 
able. For, consider two residences offered for 
sale at the same price, with the same surround¬ 
ings. One has been built with no idea as to design 
or relation to the surrounding buildings; the 


224 


ARCHITECTURAL DRAFTING 


other has been treated to correspond with the 
existing conditions, has been made attractive by 
the arrangement and style of windows, and the 
cornice has been designed to give a certain ef¬ 
fect to the other parts of the design. There is no 
question which would be the best investment. 
Work, then, with this end in view, as if it were 
your own builidng, and you wanted it to be the 
very best for the money. 

In drawing the elevations, usually each side 
of the house is shown on the drawings. The front 
elevation is made the most complete. The owner 
wants to see how his building will look when 
completed; therefore show the materials. If the 
walls are shingled, indicate by lines that there 
are to be shingles—not by covering the entire 
front with perfectly regular, mechanical lines 
representing the shingles, but with patches here 
and there over the entire front. Indicate by ar¬ 
rows and lines, similar to dimension lines, where 
the shingles are to be used. Indicate the brick 
of the foundation above grade the same way. 
Show the type of windows you expect to use; 
show the correct profile or outline of the cornice; 
the general design of the front door and the 
porch and steps; indicate the glass in the door, 
whether double strength, plate, or beveled-plate 
glass. In short, make this front elevation com¬ 
plete, so that an owner can see just the materials 
used, where used, and just how the building will 
look from the front. Very often the stairs are 
dotted on this elevation to show just how they go 


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ARCHITECTURAL DRAFTING 


225 


up to the next floor above; but this is not to be 
recommended, as it detracts from the general ap¬ 
pearance of the elevation, and there are other 
and better methods of indicating stairs, as ex¬ 
plained later. 

Very often there will be a small section of the 
house on the same sheet with the front elevation. 



Fig. 12. Front Elevation of a Residence at Champaign, Ill. 

Outline emphasized. 


This is used to give the heights of the floor-lines, 
the window lines, and the cornice lines, and not 
for showing of details. This is not objectionable, 
as the section is a separate drawing entirely from 
the elevation, and will give a means of showing 






























































226 


ARCHITECTURAL DRAFTING 


the above data without marking them directly on 
the elevation. 

Too much emphasis cannot be laid upon the 
method of finishing the front elevation. A little 
time and careful work spent on this drawing will 
very often confirm a favorable impression on the 
owner. The style of letter used and the arrange¬ 
ment on the sheet should all tend to make the 
drawing attractive. 

As a final touch, it will be found very desir¬ 
able, after the elevation is complete, to outline 
the building with a heavy line, thus emphasizing 
the general outline of the building, while the 
other lines are all uniform but lighter (see Fig. 
12 ). 

The side and rear elevations should also be 
complete in that they should show the exact ma¬ 
terials used and the exact size and spacing of the 
openings; but they need not be so carefully 
drawn nor so carefully lettered as the front ele¬ 
vation, since they are more or less a secondary 
consideration. 

The location of openings should be studied 

with the idea of the general effect on the eleva¬ 
tion, as well as on the necessary arrangement for 
the rooms. In other words, do not locate all open¬ 
ings on the plans definitely without studying the 
elevations also. Be sure that the openings are 
correctly located on the elevations so that the 
plans and elevations will agree, and not merely 
put on the elevations where they look the best 
without any reference to the plans. 


ARCHITECTURAL DRAFTING 


227 


To sum up, make the elevations true pictures 
of the building when completed; indicate the ex¬ 
tent of all materials; study the design, making it 
typical of the class of building in hand, and make 
it complete in every respect. 

Scale Details 

The Section. Having completed the plans 
and elevations, it will be necessary to make large- 
scale sections through different parts of the 
building. A section should be shown through 
every portion of the building that is of different 
construction from others. These sections are 
usually of a larger scale than the plans and ele¬ 
vations. 

In Fig. 13 we see the method of drawing and 
finishing these details. A scale very convenient 
for use is three-quarters of an inch equals one 
foot (or, as it is often called, a “three-quarter- 
inch” scale). The purpose of these sections is to 
show exactly how the building is to be put up— 
the method of supporting the cornice on the 
plate; the roof sheathing and covering; the con¬ 
struction of the gutter, with all materials named; 
the ceiling joists and method of support on the 
outside wall; the lath and plaster; the wall 
sheathing and siding or shingles; the picture 
mould; the detail of the inside window trim; the 
base around the room; the second-floor construc¬ 
tion, showing size of joists and method of sup¬ 
port on the wall; the composition of the floor, 
whether double or single, or any paper between 





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230 ARCHITECTURAL DRAFTING 

the floors; the lath and plaster of the ceiling be¬ 
low; the details of the window construction, trim 
and stool or inside sill; the base around the room; 
the method of supporting the frame wall upon 
the basement wall; the water-table; the thick¬ 
ness of the basement wall; the level of the ground 
on the outside; the basement floor inside; and 
the footing. 

Use plenty of dimension lines and explana¬ 
tory notes. In dimensioning story heights, al¬ 
ways give from finished floor-line to finished 
floor-line, or from floor to ceiling; never dimen¬ 
sion the thickness of the floor construction. In 
other words, referring to Fig. 13, we shall get 
into trouble by trying to specify exactly the 
thickness over all. This should be left without 
a dimension, by showing the plaster, noting the 
size of joists, and showing the floor, whether one 
or two thicknesses, let it come what it will. The 
thickness of the plaster will vary slightly; a 2- 
inch by 10-inch joist is not 10 inches deep; 
neither is a floor of two thicknesses 2 inches 
thick. Thus we see it is rather an uncertain di¬ 
mension. 

A sheet is usually devoted to these details. 
Sometimes as many as half a dozen different sec¬ 
tions are drawn for a residence, each showing 
differences in construction. 

Be very careful to note on the plans just 
where each section is taken, and put correspond¬ 
ing letters on the title for the section. The use 
of notes and plenty of them cannot be urged too 


ARCHITECTURAL DRAFTING 


231 


strongly. The small working drawings are very 
unreliable as to details; and consequently the 
more details, the better the contractor will un¬ 
derstand just exactly what he is to furnish, and 
will therefore be able to figure the more closely. 
These details, well executed, will prevent many 
disputes between contractor and architect, and 
between architect and owner, as well as save the 
“extra” bills from the contractor which are sure 
to arise from incomplete drawings. 

Cross-hatch or cross-section all sections or 
materials that are cut in two, using some stand¬ 
ard symbol, as elsewhere indicated, on the draw¬ 
ings. This makes a much better looking draw¬ 
ing, and makes it much easier to interpret. 

To indicate further the general treatment of 
the interior finish, the rooms having anything in 
the way of a paneled wainscot, beamed ceiling, 
or finish around a fireplace, also the sideboard, 
cupboards, and pantry fittings, should all be 
shown. The best and perhaps the most com¬ 
mon method is to draw at one-quarter-inch scale 
the different elevations of the rooms, showing 
exactly the height, width, and any features of 
unusual arrangement. Should opposite sides 
of a room or any sides be similar, after putting 
the title on one drawing, note under it: “Oppo¬ 
site, north, south, etc., sides similar.’’ There 
is usually one sheet of just such drawings as 
this to accompany the regular set of drawings. 
Since plans are usually submitted to competitive 
contractors, there is not the chance of one pro- 




232 


Details of Dining Room, 








































































































































































































































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ARCHITECTURAL DRAFTING 235 

posal or bid being lower than another because 
certain things were overlooked or purposely 
omitted. 

In Fig. 14 we see drawings of elevations and 
sections of various portions of a living room and 
dining room, giving all necessary information. 

Fig. 15 illustrates completely the drawings 
necessary to show a pantry and butler’s pantry. 

Full-Sizing. After the contract has been 
awarded, the general working drawings will 
have to be supplemented by drawings of differ¬ 
ent portions of the work at a large scale. Usu¬ 
ally these are drawn at actual or full size. In 
order to have your profiles and outlines made 
just as you intended, this method of drawing 
all parts of construction at the actual size is 
imperative. 

Take an example. You wish the plate-rail 
in the dining room made just so. Then you will 
have to draw this part of the work the actual 
size. If you do not do this, the contractor will 
put in a plate-rail of a stock pattern; that is, 
he w T ill select some pattern that he can buy from 
a planing mill, and will use this. It is the 
cheapest way to do, for him; therefore you can¬ 
not blame him for saving anything he can, if 
the exact style is not definitely shown. 

In full-sizing, it will be well for the drafts¬ 
man to be familiar with the usual method of 
doing things, making his details practical as well 
as indicating the profile. The cornice should be 
shown; the interior finish; the method of mak- 


236 ARCHITECTURAL DRAFTING 

ing the window-frames; all unusual woodwork; 
the construction of the beams for a beamed ceil¬ 
ing; all sheet-metal work, such as gutters, 
cornices, etc.; all stonework, such as water- 
tables, window-sills, and door-step; all plaster 
work, such as ornamental cornices, and method 
of supporting under unusual conditions. You 
will hear it asked: “ Why is it necessary to spend 
all this time detailing, when the contractor or 
the planing mill have their own way of doing 
these things?” There is just the point. They 
certainly have a way of doing things; but nat¬ 
urally their way is the cheapest way; therefore, 
give them details of how you want this work 
done, and see that it is done your way. Dimen¬ 
sions on full-size details are unnecessary. 

Fig. 16 is a reproduction of a sheet of full- 
size details. 

A word might be said as to the method of 
getting out these details. The drawing is first 
made on detail paper, a heavy yellow paper. A 
soft pencil should be used, as it makes the lines 
more distinct and is easily changed or erased. 
After the drawing is completed on this paper, 
then use a cheap, thin paper, and trace through, 
using a broad, heavy line and colored crayon for 
cross-sectioning the sections of the work. Yel¬ 
low is generally used for wood, red for brick, 
green for stone, blue for iron or steel, and brown 
for terra-cotta. A second tracing is also made. 
Thus we have three copies of each detail—one 
for filing in the office for future reference, and 


ARCHITECTURAL DRAFTING 


237 




































































































238 ARCHITECTURAL DRAFTING 

two for the contractor. One of the copies made 
on tracing paper is usually kept in the office, 
since it can be folded up to a convenient size and 
filed, the original and one copy on thin paper 
going to the contractor. 

REPRODUCING DRAWINGS 

The question of the method of reproducing 
drawings is an important one as to cost and 
time consumed. New methods are being adver¬ 
tised on the market every day. 

Blue-Printing. The blue-print process is the 
commonest, and generally speaking the cheap¬ 
est. There is a chemically prepared paper which 
is sensitive to the light. The paper is treated 
with a solution of citrate of iron, ammonia, and 
red prussiate of potash, and is placed in a dark 
room to dry. The drawing has previously been 
prepared on tracing cloth or paper. When the 
blue-print paper is dry, place the drawing, face 
down, on a sheet of glass, usually held in a 
wooden frame; over this, lay the blue-print 
paper, with the sensitive side down; over this, 
place a layer or two of soft cloth similar to 
Canton flannel, and over this place a board 
backing. 

Turn the frame over now, and expose to the 
sunlight for a few minutes, depending upon the 
intensity of the sunlight. After exposure, 
remove the blue-print paper, which has turned 
to a dark bronze color, and place it in a tank of 
water. Gradually the print comes out in white 


ARCHITECTURAL DRAFTING 239 

lines, leaving the background blue. These white 
lines were directly under the ink lines of your 
drawing, and the sun therefore could not attack 
that portion of the paper. Hence the water 
washed off the blue-print solution, leaving the 
white paper. 

A little experience will soon teach how long 
to expose in different kinds of weather. Prints 
may be made on cloudy days, and have some¬ 
times been made even during a mist. The expos¬ 
ure, of course, must be much longer on such 
days. The prints from such exposures are not 
so clear, distinct, and “sharp-cut ’’ as those made 
on bright days. When possible, avoid making 
blue-prints on dark days, if you expect the best 
results. 

Paper for blue-printing can be procured 
ready to use, from dealers all over the country, 
at a nominal cost. This is machine-prepared, 
and is more satisfactory than home-made. 

Blue-prints are hard on the eyes, and, having 
a blue background, cannot be dimensioned, 
noted, or to any great extent changed. Should 
small alterations be necessary on the blue-print, 
use a solution of common soda and water with 
a pen. This is not very satisfactory, but in cases 
where changes are necessary it will do. 

White-Printing. From working drawings, 
white prints can be made. This kind of print 
is just the reverse of the blue-print. Here we 
have blue lines on a white background. In order 
to make white prints, a negative first has to be 


240 ARCHITECTURAL DRAFTING 

made from the drawing. The paper used for the 
negatives is specially prepared and exposed and 
washed in the same way as blue-prints. When 
washed and dry, it is a real negative, on which 
all pencil lines are white and the background is 
black so as to exclude the sun—all the reverse 
of the drawing. This negative is then used by 
placing it over regular blue-print paper. The 
sun passes through the white lines, and is 
excluded from the rest by the black background. 
Upon washing the blue-print paper, the lines 
having been exposed to the sun are changed to 
blue; and the background, not having the sun on 
it, is washed off, leaving the white paper. 

This process makes a much better looking 
drawing than a blue-print, and is not so hard on 
the eyes. The cost is a little higher, on account 
of the negative; but after the negative is made, 
the cost is the same as for blue-prints. 

Aligraphy. Another process, know T n as 
Aligraphy, has been patented. By it, drawings 
can be reproduced on linen or paper, and the 
lines are practically as black as the original. 
They closely resemble etchings. For very fine 
work, this process makes splendid reproduc¬ 
tions; but it is more expensive than any of the 
processes above mentioned. 

Hectograph Process. Another common 
method of reproducing drawings is the hecto¬ 
graph process. This consists in making the 
drawings with suitable aniline inks, and then 
placing them face-down on a gelatine pad. After 









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VARIETY OF ELEMENTS. 















































































































































































































ARCHITECTURAL DRAFTING 241 

being in contact for about two minutes, they are 
removed, and blank paper is brought in contact 
with the pad, being in turn removed. It will be 
found to give a complete drawing similar to the 
original in scale, color, etc. Upwards of thirty- 
five copies may be taken off, depending upon 
the intensity of the original. 

The pad may be made as follows: 1 part of 
white glue to 5 parts by weight of glycerine. 
Soak the glue over night, in just enough water 
to cover it. Bring to the boiling point slowly, 
without burning; then add the glycerine, and 
thoroughly mix. Pour into a shallow pan; 
remove all air-bubbles from the surface with a 
stiff card; and allow to cool. Before using each 
time, wash thoroughly with a sponge and allow 
to dry partially before applying the drawing; 
also wash well immediately after using, to 
remove all traces of ink. 

The proportions may be varied slightly for 
different climates. A cold climate will require 
more glycerine, and a warm climate more glue. 
The pad should be stiff enough to resist pressure 
from the fingers when firmly pressed upon it. 

Other additional ingredients are sometimes 
used. Perhaps they have their advantages; but 
the mixture as described has been used very suc¬ 
cessfully. Often, in very hot weather, after a 
pad is made, it may seem too soft to work well. 
In such a case, placing the pan on a cake of ice 
will harden the mixture and make it satisfac¬ 
tory. 


242 


ARCHITECTURAL DRAFTING 


A cheaper pad may be made by using a mix¬ 
ture of a special clay and glycerine. While not 
giving so many prints as the glue pad, it can 
be used more economically for large drawings. 
Hectograph pencils may be had in many colors, 
which are used for making full-size details. 
These drawings are copied in the same way as 
the regular pen-and-ink drawings. 

The hectograph process is gradually gaining 
in favor, and in some localities it is used exten¬ 
sively. It has several features to commend it: 

(1) All materials can be represented in appropriate 
colors. 

(2) Copies are very cheap, and can be made on paper 
or prepared cloth. 

(3) The draftsman finds it convenient when making 
revisions, as parts of the drawing can be cut out and a 
correct portion inserted. No matter how badly the 
drawing is cut and patched, the prints are perfect. 

(4) In assembling different drawings on a sheet, they 
may be shifted at will, and a better arrangement secured. 

(5) When a sheet is composed of small drawings, the 
draftsman may work over the small drawings more com¬ 
fortably than if compelled to work on a large sheet. 

The hectograph process, however, has some 
drawbacks, which may be indicated as follows: 

(1) Small details cannot be shown so clearly, as the 
lines must be quite heavy if a number of prints are 
required. 

(2) The drawings fade more or less if exposed to a 
bright light, but they are permanent enough for most 
work. 

(3) Some draftsmen do not like to use the inks, as 


ARCHITECTURAL DRAFTING 


243 


they are sticky and soil the fingers. This, however, should 
apply only to the inexperienced. 

Hectograph inks may be purchased of dealers 
everywhere, in all colors. Below are suggested 
colors for various sections of materials: 

Purple—For lines in general, outlines, profiles, etc.; 
also for sections of plaster, and concrete. 

Red—For dimension lines, and for sections of brick¬ 
work. 

Blue—For iron, steel, flashing, etc., in section. 

Brown—For sections of terra-cotta. 

Green—For sections of stone or marble. 

Yellow—For wood. 

For the blue-print process, the drawing to be 
reproduced is preferably done on tracing cloth, 
on the rough side, in black ink. Erasures may 
be made on this, and the work corrected; but 
the finished drawing has to be complete in every 
respect, as every line is reproduced just as 
drawn. 

For the hectograph process, we shall need to 
make the lines much heavier, and may use 
colored inks. Mistakes cannot be erased, but 
are cut out, and a new piece of paper placed over 
the hole, and the drawing continued. 

Tracing cloth makes the most satisfactory 
material all around for the original drawing. It 
is translucent or semi-transparent, will make 
good prints by almost any process, and is much 
more desirable than paper for filing away and 
for constant use in the drafting room. 

The use of colored inks is not to be recom- 


244 ARCHITECTURAL DRAFTING 

mended. They make the tracing look very 
pretty, but they print very poorly, some shades 
of green being hardly visible on the blue-print. 
Red reproduces very faintly, and when this color 
is used for dimension lines they should be heavy. 
Black is the most serviceable color to use. In 
steel detailing, the entire drawing is done in 
black—even dimension lines. 

ARCHITECTURAL FORMS 

Having considered the general method in the 
drawing of architectural plans, we shall now 
consider some of the general forms employed to 
represent different parts of the work. 

Conventional Forms and Symbols. First 
there must be some adopted form for represent¬ 
ing materials. It will be found throughout the 
country, that each architectural firm has its own 
architectural forms and symbols. This is rather 
confusing, since it requires a draftsman chang¬ 
ing offices, or Building Departments checking 
plans, to become familiar with the symbols as 
used by each office. 

In Plate A are given some general forms for 
representing materials. 

Fig. 1 represents brick. A section of a brick 
wall should be sectioned as shown, by parallel 
lines at 45 degrees, slanting down to the left. It 
might be well to repeat here what has been said 
about the use of colored inks for drawing. 
Except for dimension lines, avoid the use of 
colors. The materials may be indicated as shown 


ARCHITECTURAL DRAFTING 


245 



F!Q. J. 


BQICK 



BUBBLE. 5T0NF 


F/G. 2. . 




CUT STONE 



CONCRETE 


TERRA COTTA 


F/G . 3 


WOODEN PARTITION - 
LATHED AND PLASTERED 

FIG. G. 

TILE PARTITION- 
PLASTERED. 

FIG. 7 

BR/CK WALL- FURRED, 
LATHED AND PLASTERED. 

F/G. 6. 


SOLID PLASTER PART¬ 
ITION ~ PLASTERED. 


F/G. 9. 




Plate A. Conventional Symbols for Representing Materials on Ar¬ 
chitectural Drawings, 


























246 


ARCHITECTURAL DRAFTING 


by varying the texture of the line and also by 
different forms of dotting. 

Fig. 2—We use alternating lines—solid and 
dashes—at 45 degrees to represent rubble stone 
such as is found in most basements. 

Fig. 3—We use solid lines running at 45 
degrees to each other and in opposite directions, 
to represent cut-stone work such as sills for 
windows and doors, chimney caps, and any kind 
of finished or dressed stone. 

Fig. 4 represents concrete. This symbol is 
composed of small, wavy lines, with occasional 
triangular shapes to represent the stone. This 
symbol may be used to represent the concrete 
such as would be used in a solid wall or 
reinforced concrete for floors and other similar 
constructions. 

Fig. 5 illustrates the method of showing 
terra-cotta. This is the same as for brick, with 
the lines running in the opposite direction. 

For representing an interior partition of a 
frame building, the method shown in Fig. 6 is 
perhaps the most satisfactory. Plaster is repre¬ 
sented by parallel lines to opposite sides of the 
wall. 

Very often, in fireproof buildings, partitions 
are built of hollow tile and plastered on both 
sides. Fig. 7 illustrates the method of indicating 
such a partition. 

Where a brick wall is furred on the inside and 
then plastered, we use the ordinary symbol for 


ARCHITECTURAL DRAFTING 247 

the brick wall, and show the plaster away from 
the wall, as in Fig. 8. 

Very often, instead of using the partition as 
shown in Fig. 7, it will be built up solid of plaster 
2 inches thick with a layer of expanded metal 
imbedded. This partition is shown in Fig. 9. 
It will be found a very satisfactory partition, 
requiring less floor space, and equal in every way 
to any other fireproof partition. 

On the basement plan, various lines of pipe 
should be shown. There should be a porous tile 
drain, in damp soils, all around the outside of 
the basement walls, at the footing line. Such 
drains are constructed of porous farm tile, laid 
with butt joints and no cementing of any kind. 
The tile being porous, the water in the soil perco¬ 
lates through the walls of the tile, and is carried 
away. These drains are indicated as shown in 
Plate B. 

For the sewer connections inside the build¬ 
ing, and extending at least six feet outside the 
basement wall, the pipe should be cast-iron and 
have calked joints. Such pipes are shown on 
the basement plan as in Plate B. Connected to 
this cast-iron pipe outside the basement wall, a 
vitrified tile drain should be used, with cemented 
joints. Such pipe is also shown in Plate B. All 
these pipe lines should be shown in black on the 
drawing. 

There are certain lines used in a drawing for 
reference, such as axis lines —that is, when a 
room or building is symmetrically arranged 


248 


ARCHITECTURAL DRAFTING 


POROUS TILE. DPAJMS. 


/ROT/ PIPE DQA/NS. 


V/TQ/E/ED SEWEQ P/PE. 


7 'he Above: Should Be Shown With Bl ac K Lines. 


AXIS LINES (Red). 


BUILDING LINES (Red). 


DOTTED El A/E S EO/3 GENERAL USE. 

/<S'-Q" 


D/MENS/ON E/AIES (Usually Red With 

Beach Arrows). 

Plate B. Conventional Methods of Representing Drain and Sewer 
Pipe, Axis Lines, Building Lines, Dimension Lines, etc. 













ARCHITECTURAL DRAFTING 24? 

around a center line. In order to make suck 
axis lines distinct from general lines, they are 
usually made as shown in Plate B. 

When there are offsets or projections on a 
wall, such work is measured from certain lines 
established as building lines (see Plate B). 
Usually the outside wall line of the first story is 
taken as this reference line; and the basement 
wall line, the second-story line, the eave fine, 
etc., are all measured as projecting from this 
line. 

All dimension lines are to be noted as shown 
on this same plate, in which the arrow-heads 
are black, the connecting fine is red, and the 
figures are in black, always above this line. This 
is the best practice, though sometimes dimen¬ 
sions are placed in the center of the line, the line 
being stopped to allow the figures to be inserted. 
This method takes more time and is not so 
practical, since the dimension line is broken and 
in some cases there might be a dispute as to just 
how much the dimension is intended to include. 

For lighting, there are standard symbols 
adopted by the National Electrical Contractors’ 
Association of the United States. These are 
published on a card convenient for reference, and 
copies may be had by applying to the Secretary. 
Another form of symbols has been adopted by 
the Boston Society of Architects, copies of which 
may also be had on application. The latter sym¬ 
bols are shown on Plate C. These are given for 
convenience in laying out plans, and are not 


250 


ARCHITECTURAL DRAFTING 


This Specification is based upon the use of the follovumq symbols 
and of such others aa motf 6c used and explained on the Plans. 


ELECTRIC 

GAS 

COMBINATION 

CEILING OUTLET 




WALL OUTLET 

2. Lights 

W 



FLOOR OUTLET 
t Light: 


■ 

a 

EASE OUTLET 

JSL 


-H- 

5 Wi TCH [-C - Dotted Line shows Switch 

1 vJ Control. 

PUSH BUTTON 0 

DANK OF SUTTON5 

BELL. § 

A NNUNCtA TOG r^i 

CABINET 

SPEAKING TUBE [-^ 

HOUSE TELEPHONE 

PUBLIC TELEPHONE A. 

HEIGHTS OF STORIES - TOP 

!* r rr in. 2.' ytx ft in. 

5™ FT in 6™ FT IN 

9' rH FT- IN. IO™ FT- IN- 

9 TO TOR BT FT /*. 

3*° FT. IN. 4 VH FT. IM 

7™ *nr. m Q™ FT. //y. 

IT* nr- in. \z r * FT. 

HEIGHTS OF CENTER OF WALL OUTLETS. 

un/cjt otherw/j* s/omcitied. 

LIV/NG /ROOMS- 3 L G’ OFFICES - S'-O" 

CHAM BER S- 3- O" CORRIDORS - G’-JT " 

HEiGHT OF S WITCH E S ~ Unless otherwise specified ~ 4 ~ O* 


Plate C. Standard Symbols for Kepresenting Fixtures, Electric 
Outlets, etc. 

Adopted by the Boston Society of Architects. 




























ARCHITECTURAL DRAFTING 251 

intended to be complete in every respect. It is 
essential to show the location of the light outlets 
in all rooms; also whether they are to be gas, 
or electric, or a combination of both. Push¬ 
buttons, bells, and telephones are also indicated. 
If these locations are not shown, the contractor 
for this work will naturally place them in a posh 


[ 75 jF ~\ o 

A 



Fig. 17. Conventional Symbols for Heating Apparatus. 

A—Steam or Hot-Water Radiator; B—Hot-Air Register. 

tion requiring the least amount of pipe, wire, 
etc. Therefore show all of these fixtures, and 
there can then be no dispute as to the true intent 
of the plans and specifications. 

For the heating, about all that is necessary is 
to show the location of the registers or radiators, 
marking the number of square feet of radiation 
on each radiator. The usual method is shown in 
Fig. 17 (A) for steam or hot water, and in Fig. 
17 (B) for hot air. The specifications should 



Fig 18 Conventional Representation of Flues for Air Supply 
and Ventilation. 











252 ARCHITECTURAL DRAFTING 

describe the kind of heat, and go into detail 
about pipe, fittings, etc. 

In hospitals, public buildings, and school- 
houses, where there are a number of occupants 
in each room, it will be necessary to furnish a 
fresh-air supply, also a vent flue. These are all 
figured, and should be located conveniently. 



Fig. 19. Sketch Plan Showing Arrangement of Furniture. 


The method of figuring the correct location for 
such work will be considered under “Heating 
and Ventilating.” The conventional method of 
showing flues for air supply and ventilation is 
shown in Fig. 18. 

For furniture, certain conventional forms are 
used, and shown on all plans. The furniture of 
the bedrooms and bathrooms is usually laid out 
on the plans, since these are usually made as 



























ARCHITECTURAL DRAFTING 253 

small as practicable; therefore the furniture 
and fittings are laid out to make sure that there 
will be room to get them all in. This applies to 
the cheaper classes of houses, for in the larger 
and more expensive residences the rooms are 
always amply large to accommodate all the fur¬ 
niture and fittings desirable. In Fig. 19, a bath¬ 
room and bedrooms are laid out, the furniture 
being indicated by numbers, (1) representing 
the lavatory or wash-bowl, (2) the closet, 
(3) the bathtub, (4) the bed, (5) the chiffonier, 
(6) the dresser, and (7) a table or writing desk. 
See also Fig. 20. 

Sometimes a client has furniture he wishes 
to put into a new home. It will be found very 
convenient to get the dimensions of such furni¬ 
ture, and cut out pieces of cardboard the exact 
sizes of this furniture according to the scale of 
the plan. Then lay them on the plan as drawn, 
and see how they will fit wall spaces, nooks, etc. 
By this method, pieces can be arranged, and it 
will very soon be shown whether or not the 
rooms will accommodate the furniture. This 
will be found very convenient in all classes of 
work (see Fig. 20). 

Below are given the dimensions of some of 
the common pieces of furniture. These sizes 
will vary somewhat, but in general they will 
be accurate enough in laying out work. 

Dining Tables—3 ft. 6 in. to 4 ft. wide, and to extend 
to 10 ft. to 12 ft. by extra leaves, and 2 ft. 5 in. high.. 

Writing Tables—2 ft. 6 in. high. 


254 


ARCHITECTURAL DRAFTING 



Ordinary Tables—2 ft. 6 in. high. 

Beds, Single—3 ft. 6 in. wide; 

Beds, Three-quarter—4 ft. to 4 ft. 6 in. wide; 
Beds, Double—4 ft. 6 in. to 5 ft. wide. 

All beds should be 6 ft. 8 in. long inside. 
Dressers—1 ft. 6 in. to 2 ft. by 3 ft. 5 in. 
Couches—2 ft. 6 in. by 6 ft. 8 in. 



































































































ARCHITECTURAL DRAFTING 


255 


Chiffoniers—2 ft. by 3 ft., and 4 ft. 6 in. high. 

Sideboards vary according to design, 4 ft. to 6 ft. long, 
and from 2 ft. to 2 ft. 2 in. deep. 

Pianos, Upright, vary, being usually 3 ft. 3 in. by 6 ft. 
6 in. long, and 4 ft. to 4 ft. 9 in. high. 

Bookcases—10 in. to 16 in. deep, any length and height. 

Chairs and Seats—Usually 17 in. high at front, 16 in. at 
back, and the seat is usually 17 in. high by 16 in. inside; the 
back, from 1 ft. 6 in. to 1 ft. 8 in. high, slightly inclined 
at the top. 

For plumbing fixtures, consult any plumbing cata¬ 
logue. The washstand varies, 18 in. deep by 2 ft. long 
being about the minimum. The bathtub varies from 3 ft. 
6 in. to 4 ft. 6 in. long, about 1 ft. 11 in. high above the 
floor, and 2 ft. wide across the rim. Closets are about 
1 ft. 4 in. wide, and about 2 ft. from the wall. 

Ranges—26 in. to 30 in. by 36 in. by 42 in. 

Ranges, Gas—26 in. by 34 in. 

Lunch Counters—Height, 3 ft. 3 in. 

Stool, 2 ft. 2 in. 

Counter projects 9 in. and is 2 ft. 
2 in. wide. 

Foot-rest, 7 in. high and 9 in. from 
counter. 

Urinals—26 in. to 30 in., center to center. 

Rugs—4 ft. 6 in. by 7 ft. 6 in. up to 11 ft. 3 in. by 15 ft. 

The above dimensions are only general, but 
will be of assistance in laying out the furniture 
of a house. 

MATERIALS OP CONSTRUCTION 

There will be found a great variety of materi¬ 
als for the construction of buildings, nowadays. 
In some localities, one material will be used 
more than others; for instance, in the vicinity 


256 


ARCHITECTURAL DRAFTING 



Fig. 21. Elevation of a Porch. 

See also Figs. 22 and 23. 






















SHADOWS CAST UPON AN ODDER OF ARCHITECTURE. 


PLATE D—Architectural Drafting, 



















































ARCHITECTURAL DRAFTING 


257 



Detailed for Stone Construction. 



Fig. 23. Porch of Fig. 21 
Detailed for Wood Construction. 







































































































258 


ARCHITECTURAL DRAFTING 


of a stone quarry, stone will usually be cheaper 
than anything else—even in some cases cheaper 
than wood. Should your client be interested in 
a brick concern, brick would undoubtedly be 
used. In a locality where timber is cheap, that 
material would be largely employed. 

For the cheaper class of work, we find wood 
to be the cheapest material, although, within the 
past ten years or so, wood has advanced in price 
at a great rate. The kind of wood used will 
vary with each locality. In some sections—espe¬ 
cially the South—yellow pine will be used; in 
our Western States, fir and local varieties will 
be selected. An architect in a new locality, 
therefore, should become familiar with the local 
woods used, and should govern his work, such 
as spans of beams, interior finish, etc., by these 
conditions. The use of terra-cotta for the facing 
of masonry walls, for ornamental courses, cor¬ 
nices, and window-sills, is quite common. Since 
this is a product made of clay, properly mixed, 
moulded, and burned, it can be treated as plainly 
or as elaborately as the design of the building 
warrants. Terra-cotta, of course, is used only 
with masonry, such as brick, stone, or concrete. 

Fig. 21 shows the elevation of a porch, and 
Fig. 22 shows this porch detailed for stone con¬ 
struction; while Fig. 23 shows the same porch 
detailed for wood. 


AECHITECTUEAL DBAFTING 


259 


SHADES AND SHADOWS 

In order to prepare sketches and make them 
attractive, a brief treatment of Shades and 
Shadows will be taken up, the main general rules 
and principles being explained, which may be 
applied to ordinary architectural drawing. 

By the use of shades and shadows, very im¬ 
portant effects are produced. The general pro¬ 
portions of the cornice, for example, are empha¬ 
sized by using shadows. The relative amount 
of window area to wall area is clearly shown by 
the use of shadows. 

The light is always assumed as coming over 
the left shoulder of the person looking at the 
drawing, and at an angle as explained later. 
This assumption is always made, being merely a 
conventional or customary way of considering 


Fig. 24. Fig. 25. 

Illustrating Conventional Method of Considering Rays of Light in 
Architectural Drafting. 

the light. The idea intended is to produce the 
same effect on a drawing that the sun in this 
one position would produce on the building. 
While the sun would actually produce a shadow 
on one side of the building at one time, and on 
another side at another time, in architectural 





































260 ARCHITECTURAL DRAFTING 

drawing this variation is not shown. No matter 
what elevation or side of the building is being 
considered, the light is always from the same 
direction. 

Thus we see that in Figs. 24 and 25 the sun 
really would make one side always in shadow, 
but we do not so consider it. In Fig. 24 we 
see the side A is in sunlight, and the side B is 
in shade. Looking now at Fig. 25, we see side 
B in sunlight, and 0, which was the rear end, 
now in shade. This is the conventional method 
of considering the rays of light for architectural 
drawings. No matter what elevations or draw¬ 
ings are considered, or how many of the same 
building on the same sheet, the direction of the 
rays of light is fixed. 

Perhaps it will make the understanding of 
this subject clearer if we define the terms shade 
and shadow. That portion of a building or 
drawing is said to be in “shade” which is turned 
away from the assumed rays of light; or, it 
receives no rays of light, in contrast to the sides 
which are in light or upon which the light falls. 

If a body is placed between the light and a 
plane upon which the rays might fall, such a 
body will prevent a portion of the rays from 
striking the plane, therebj^ causing a shadow 
upon the plane. 

All rays of light are assumed as parallel and 
considered as straight lines. 

The rays of light are assumed as coming over 
the left shoulder, or sloping downward and 


ARCHITECTURAL DRAFTING 


261 


backward. This is the diagonal of a cube. The 
projections of this diagonal in the vertical plane 
and in a horizontal plane are at 45 degrees, while 
the true angle of the diagonal with the plane is 
slightly less than 35 degrees 16 minutes. If we 
assume the side of the cube as 1, then the true 
length of this diagonal is nearly one and three- 
quarters. In Fig. 26, we see the cube and the 
diagonal drawn as a heavy line with an arrow- 




Fig. 26. Drawing Showing As- Fig. 28. Elevation of Point 
mimed Direction of Light. and Shadow. 






Plane of 

5 hs do vs/ 


Point-'* 


rr 

I X 

■1 


Fig. 29. Plan of Point in Space 
and Plane. 

Shadow of a Point in Space. 


Fig. 27. Elevation and Plan of 
Cube of Fig. 26. 











262 


ARCHITECTURAL DRAFTING 


head indicating the direction of the light. Fig. 
27 shows the elevation and plan of the same 
cube. 

The shadow of a point is where the ray of 
light surrounding the point intersects the plane 
upon which the shadow falls. In Fig. 28, we 
see the light surrounding the point, and inter¬ 
secting the plane, giving the shadow of the point 
upon the plane. The shadow is located as far 
down and as far to the right of the point in 
space as the point is from the surface or plane 
upon which its shadow falls. Fig. 29 shows the 
plan of the point, its distance from the plane, 
and the plane. 



Fig. 30. Elevation of Line and Fig. 31. Plan of Line in Space 
Shadow. and Plane. 

Shadow of a Line Parallel to Plane of Shadow. 

The shadow of a straight line in space is the 
intersection of the light surrounding this line 
with the plane of shadow. By casting the shad¬ 
ows of the extremities of the line and connecting 
these points of shadows, we have the shadow of 
the line. All points of the line in space will 
cast shadows upon the plane as far down and as 
far to the right as the point is from the plane. 







ARCHITECTURAL DRAFTING 


263 


If the line is parallel to the plane, the shadow 
will be equal in length and parallel to the line 
itself. See Fig. 30 for an elevation, and Fig. 31 
for the plan of the line and plane. 

If the line in space is not a straight line, then 
the shadow of the line may he found by casting 
the shadows of any number of points on the 
line, and connecting these. The greater the 
number of points of shadows cast, the greater 
will be the accuracy of the work. In Fig. 32 



E.L E.VATION* PLAN 

Fig. 32. Fig. 33. 

Shadow of an Irregular Shape which is Parallel to Plane of 
Shadow. 


we see the shadow of an angle or L-shape cast 
on the plane of projection; Fig. 33 shows the 
plan of the angle. 

The shadow of a straight line perpendicular 
to the plane upon which the shadow falls, is a 
straight line at 45 degrees, no matter what the 
outline of the surface is upon which the shadow 
falls (see Figs. 34, 35, and 36). 

The shadow of a straight line parallel to the 
plane upon which the shadow falls, is an irregu- 








264 


ARCHITECTURAL DRAFTING 


lar line giving the true outline of the surface 
(see Fig. 37). 

The shadow of a perpendicular line on a roof 
is therefore a line which gives the true slope of 
the roof, since the line is parallel to the plane, 
and therefore casts a shadow the true shape of 
the surface upon which it falls. 



rig. 34. Fig. 35. 

Shadow of a Line which is Perpendicular to lane of Shadow. 



Fig. 36. Showing Shadow of 
a Line Perpendicular to 
Plane of Shadow. 



Fig. 37. Showing Shadow of a 
Line Parallel to Plane of 
Shadow on a Moulded 
Surface. 


The shadow of a straight line inclined to the 
plane upon which the shadow falls, is a straight 





























































ARCHITECTURAL DRAFTING 265 



Fig. 38 Shadow of a Line Inclined to Plane of Shadow. 



Fig. 39. Shadows of a Square and a Circle Parallel to Plane of 

Shadow. 




















266 


AKCHITECTUEAL DEAFTING 


line connecting the shadows of the ends of the 
line (see Fig. 38). 

As in the case of a line parallel to the plane 
upon which the shadow falls, the shadow is equal 
in length and parallel to the line, so it is with 
surfaces —the square, rectangle, octagon, etc. 
If parallel to the plane of shadows, the shadow 



Fig. 40. Shadows of a Square and Circle Perpendicular to Plane of 
Shadow. 

will be equal in size and shape to the figure ("see 
Tig. 39). 

A square perpendicular to the plane of 
shadow will cast a diamond-shaped shadow, for 
two of the lines are parallel to the plane, and 
two are perpendicular to the plane (see Fig. 40). 


























ARCHITECTURAL DRAFTING 


267 


Having stated a few principles of casting 
shadows, these will be applied to a few common 
examples. 

Take an example of a brick projecting from 
a wall (Fig. 41). We apply the principles as 



ELE.VA.TI ON 



PLAN 

Fig. 41. Shadows of Projections from Plane of Shadow. 



PLAN 

Fig. 42. Illustrating Principles of Shadows. 

stated, to each edge of the brick. The top, bot¬ 
tom, and side faces of the brick are perpendicu- 





































































268 ARCHITECTURAL DRAFTING 

lar to the plane, therefore the shadows will be 
rectangular in shape. 


Figs. 42 and 43 show a further application 
of the foregoing principles. 



Plate D shows the shadows as cast upon an 
Order of architecture, illustrating also how 
much clearer the drawing is when it has the 
shadows worked out on it. 

The above principles will give a general 
understanding of the subject. 

DETAILS OF CONSTRUCTION 

It is essential to know the usual method of 
detailing different portions of the building. For 
the clear understanding of some of the impor¬ 
tant parts of a building, there have been pre¬ 
pared some typical details. The reader, having 
become familiar with the details shown, can 
adapt them to any sort of building. 

Cornice. The cornice is the projection at the 
top of the building, made more or less elaborate. 
There are several kinds of cornices—the box 
cornice, as shown in Fig. 44, and the open cor¬ 
nice, as shown in Fig. 45 (a and b). Referring 






















ARCHITECTURAL DRAFTING 


269 


to Fig. 44, there is the crown-mould A, the fascia 
B; the planceer or soffit C; the lookout D; the 



brackets E ; the dentil course F. Not all cornices 
have all these parts. The plainer ones may be 
without the brackets E and the dentils F; or 














































270 


ARCHITECTURAL DRAFTING 


more elaborate cornices may have more mem- 
bers. The closed cornice always has the gutter 
built into the upper members; the open cornice 



or b). 

The gutter, in the best work, is made of cop¬ 
per; in ordinary work, of galvanized iron; and 
in the cheapest class of work, tin is used. The 
durability of these materials is in the order 
named, the copper wearing usually the life of 
the building. Galvanized and tin gutters have 
to be kept well painted; but even with good 
care, the life of these two materials is limited. 

One important feature of a good gutter is 









ARCHITECTURAL DRAFTING 271 

to have the metal run well up under the roofing 
material, and out over the crown-mould. This 
keeps any water from overflowing up under the 
roof if the gutter becomes choked with ice or 
leaves. The gutter should be well pitched or 
graded to the outlets. The gutter outlets are 
in turn connected to leaders or down-spouts. 
These down-spouts are made, usually, of the 



Fig. 45b. Type of Open Cornice Known as Close-Eave Cornice. 

same material as the gutter. The shape of the 
down-spouts may be either round or rectangu¬ 
lar; a very common form is made of corrugated 
iron, either round or rectangular. The gutter, 
especially if a hanging gutter, must be securely 
fastened to the roof at intervals of two or three 
feet, by means of some sort of hanger. The 
down-spouts must be securely fastened to the 
wall by some approved method. 

Floor Construction. The floor construction 
does not vary much (see Fig. 46). In this figure 








272 


ARCHITECTURAL DRAFTING 


we have the usual construction and method of 
support at the second or upper floor line. The 
joists must be of ample size, not only to carry 



Fig. 46. Common Floor Construction at Second-Floor Line. 

the load safely, but to be stiff enough not to sag 
or vibrate under a load, since this would crack 
the plastering or the ceiling below. On the 
joists is laid an under-floor, usually of boards 
Vs inch thick, laid diagonally at 45 degrees with 
the joists, and spiked with two nails on every 
























ARCHITECTURAL DRAFTING 273 

joist. The flooring laid in this manner braces 
the building, and resists any tendency to twist. 

In the best construction, we use some sort 
of deafening material between the upper and 
under floor, to deaden sound. The upper floor 
is of maple, oak, or yellow pine of matched or 
tongued-and-grooved boards, with the boards 
parallel to one side of the room. This floor is 
blind-nailed; that is, the nails are driven in at 
the intersection of the tongue and the vertical 
edge, as shown in Fig. 47. This keeps all nail- 



Fig. 47. Section Showing Blind-Nailing. 


heads hidden from view. The upper floor should 
be thoroughly kiln-dried—that is, dried arti¬ 
ficially to drive out the greater part of the 
moisture, so that when it is finally laid, it will 
not dry out in the building and open up ugly 
cracks. For this reason the finished floor should 
not be laid until the plastering is thoroughly 
dry. The under side of the joists is lathed and 
plastered. 

Around openings, chimneys, or stair-wells, 
the joists are supported at the ends by means 
of a header, or a joist running at right 
angles to them, to which they are securely 







274 ARCHITECTURAL DRAFTING 

spiked; or they may rest on top of a ribbon or 
%-inch board let into the studding, the con¬ 
struction being similar to the support for the 
ceiling joists as shown in Fig. 44. 

At the first-floor line, we have to build a sill 
upon the basement wall; this sill for ms a sup¬ 
port for the joist, and also gives a nailing for 
the studding. The method is clearly shown in 
Fig. 48. 

Lath and Plaster. The interior finish of 
almost all residence work is lath and plaster. 
The walls, if of wood, and the ceiling, are lathed 
with good, sound lath, free from blue sap or 
bark, and of white pine or spruce. They should 
be spaced at least 1/4 inch apart, and the plaster 
pressed firmly onto them so as to make sure 
that there will be a good key for holding the 
plaster. All lath on vertical walls should be 
put on horizontally, and there should not be a 
vertical joint of more than 18 inches between 
any series of laths. Under no consideration 
should lath be put on a vertical wall other than 
horizontally. In hot weather, it will be well 
to wet the lath before applying the plaster, as 
then they will not absorb so much water from 
the plaster. 

Plaster is usually put on in three coats for 
woodwork, and in two coats for brickwork. The 
first coat consists of slaked lime, sand, and long, 
clean cattle hair or fiber, this hair or fiber being 
used to make the plaster hold together better. 

The first or scratch coat is applied and 


architectural drafting 


275 



Fig. 48. Floor Construction at First-Floor Line. 

pressed well into the spaces between the lath. 
It is this plaster getting in between the lath and 
falling over onto the lath, which forms the key 
or clinch for the plaster. This coat is then 
scratched with the trowel all over, in all direc¬ 
tions. This scratching roughens up the surface, 
and makes a better surface for the second coat 
to adhere to. 

The second or brown coat is a mixture ot lime 


























276 ARCHITECTURAL DRAFTING 

putty, sand, and a little hair or fiber, and is 
applied after the scratch coat has partially 
dried. This brown coat is brought out to a true 
line for all walls and ceilings, and corners are 
made true and sharp. There are placed around 
all openings and back of all chair rails, base¬ 
boards, etc., small strips % inch thick for three- 
coat work, and % inch thick for two-coat work, 
by 1% inches wide. These are called grounds, 
and serve as a guide for the plaster (see Figs. 
71 and 72). The third coat, sometimes called 
the white or skim coat, is a mixture of lime putty 
and white sand, with a little plaster of Paris. 
This is a thin, white coat, put on and rubbed 
down until hard, giving a hard white surface. 
Sometimes marble dust is added, which makes 
it harder and gives a little more polish to the 
surface. If a sand finish is desired, instead of 
the white coat as above described, the third coat 
is mixed with lime putty and coarse sand. 

Flashing and Counter-Flashing. By flashing 
and counter-flashing is meant metal protection 
for the intersection of surfaces, to keep out the 
weather. Take an example of a chimney going 
through a roof. Some means must be provided 
to prevent snow and water from coming in 
through the space between the vertical side of 
the chimney and the roof. This is accomplished 
by using sheet metal—either copper, galvanized 
iron, or tin—and fastening it under the roof 
covering, turning it up against the chimney, as 
shown in Figs. 49 and 50, the piece marked A. 


ARCHITECTURAL DRAFTING 277 

To prevent the water running down the side of 
the chimney, a cover-piece, called the counter¬ 
flashing, is fastened into a mortar joint of the 
brickwork, and turned down over the flashing. 
The counter-flashing should extend to within 
two inches of the bottom of the flashing. This 
same method of protection applies to joining a 
roof to a vertical wall, the protection at the 
outside of a window-frame, or any other place 
needing similar protection. 



Fig. 49. Section Showing Flashing and Counter-Flashing. 

Shrinkage. A word might be said about 
shrinkage. All lumber, when exposed to beat, 
will shrink, owing to the moisture drying out. 
In all wooden construction, all parts should be 
carefully framed together to reduce the shrink¬ 
age to a minimum. One common error in 
framing is shown in Fig. 51. The girder rests 
upon the post below, and the post from above 
rests upon the girder. We can see at a glance 









278 


ARCHITECTURAL DRAFTING 



Tig. 60. Flashing and Counter-Flashing around a Chimney. 

what happens when the girder commences to 
dry out. It will shrink, causing the post above 
to settle, which will affect the part of the build¬ 
ing carried in this way. Pig. 52 shows a much 
better way of framing these posts. The post 
above rests directly on the post below; and the 



F4r. 61. Erroneous Method. Fig. 62. Correct Method. 
Framing of Posts and Girders to Counteract Effects of Shrinkage. 



























ARCHITECTURAL DRAFTING 


279 


girder is carried by the steel plate as shown, or 
by means of a cast-iron post-cap. By this means 
the shrinkage in the girder does not affect the 



Tig. 53. Section of Solid Door. 


construction above. Carry out this same idea 
in all framing. When one partition comes over 
another, carry it on the cap of the partition 
below, and not on top of the floor construction. 

Doors. Doors are of two kinds—the stock 
door and the built-up door. The stock door is 
made solid, with a simple bevel called an 0 . G. 
(or Ogee). The stock doors are usually V/ s 
inches, 1% inches, and 1 % inches thick (see Fig. 
53). The built-up door has a core of %-inch 
pieces of pine glued together; this is covered 
with thin sheets of wood y 8 inch thick, called 



Fig. 54. Typical Section of a Built-Up Door. 

veneer, which is firmly glued to the core. The 
veneer is made of wood to match the interior 
finish of a residence. 

Fig. 54 shows a typical section of a built-up 
door; and Fig. 55 shows elevations of different 























280 ARCHITECTURAL DRAFTING 

doors, with the names of the various parts of a 
door. 

All openings, either door or window, should 
have the rough framing doubled around them. 

At the bottom of the door we have the 
threshold, which is a raised piece, usually of oak 
or some other hard wood. This gives a chance 
for the door to swing clear of the carpet or 
rugs. For different details of door trim, etc., 
see Fig. 56. 


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rig. 55. T; 

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Leled Doors. 



The door is hung in a wooden frame which 
is securely fastened to the framing of the house. 
The inside and outside casing covers the space 
between the door frame and the rough framing. 
See Fig. 56 for a section through a door. 

Porch Construction. In Fig. 57 (also Fig. 
























































ARCHITECTURAL DRAFTING 


281 



Fig. 56. Sections of Front Door and Side Lights. 
















































282 


ARCHITECTURAL DRAFTING 





Fig. 57. Part Elevation and Section Showing Method of Porch 
Construction. 
































































ARCHITECTURAL DRAFTING 


283 



Fig. 58. A Typical Fireplace Construction. 































































































































































284 


ARCHITECTURAL DRAFTING 


23), we see a part elevation and a section show¬ 
ing the method of porch construction. The floor 
construction will be the same as for ordinary 
floor construction, except that only one thick¬ 
ness of flooring is used, and the boards must run 
at right angles to the house, and have a slight 
pitch away from the building. This allows the 
water to drain away from the building. In the 
best construction, the flooring is put together 
with white lead, thus insuring a perfectly tight 
joint to keep the water from soaking in at the 
joints, and thus causing the floor to rot. 

Fireplaces. Fig. 58 shows a typical fireplace 
construction. The flues are all dotted on the 

FOR 9’6" 

FOR 9 - 0 ’ 

STRAIGHT 
STAIR FOR 
6-6'CEIUNG. 

HEIGHT. 


Fig. 59. A Simple, Straight Stair. 

elevation. There should be an ash-chute from 
each fireplace connected to an ash-pit in the 
basement. There should be a damper in the 
throat of the fireplace to regulate the draft. All 
fireplaces should be lined with firebrick. 

Stairs. For stair construction, see Figs. 59 
to 65 inclusive. The simplest stairway is the 
one that has no turns in it, or the one shown in 
Fig. 59. As laid out, this stair is for an 8 ft. 6 




















ARCHITECTURAL DRAFTING 


285 


m. ceiling. Should the ceiling be higher, other 
risers may be added. 

In Fig. 65 are shown the customary details. 
The riser is known as the vertical portion, and 
the tread as the horizontal portion. The main 
supports are usually 2 by 10-inch or 2 by 1 2-inch, 
notched to fit the treads and risers, and are 



\ STAIRS WITH 
/ONE LANDING. 
DRAWN POH 
10-0" CEILING. 



THIS STTAIR. WILL GIVE 
HEAD ROOM FOR PASS* 
AGE UNDER LANDING. 


Fig. 60. Fig. 61. 

Types of Stairs with One Landing. 



called carriages. The balusters are the upright 
spindles or ornamental jjieces supporting the 
hand-rail. 

Various heights of riser to tread have been 
tried, but the one found most satisfactory is to 
make the riser from 7 inches to 7 y 2 inches. The 
usual rule for figuring the treads and risers is 






















































































286 


ARCHITECTURAL DRAFTING 



Tig. 64. Elevation of Stairway, Giving Necessary Information. 



























































ARCHITECTURAL DRAFTING 287 

to make the sum of a tread and riser equal to 
17 inches or 17 y 2 inches. From this we see that 
the higher the riser, the narrower will be the 
tread. If we make the riser 7 y 2 inches, then the 
tread should not exceed 10 inches. The width 
of tread is exclusive of the nosing, which is 
usually iy 2 inches. 



Pig. 65. Section through Stairs, Showing Customary Details. 


Stone stairs, or stairs without a nosing, will 
have to be wider. 

For figuring the number of risers, divide the 
height from floor line to floor line (in inches), 
by the height of one riser; the result will be the 
number of risers. 

Fig. 60 shows a stairway with a landinj 
Fig. 61 is another form of stair with a landing. 

Fig. 62 is a combination front and back 

















288 ARCHITECTURAL DRAFTING 

stairs. There are separate stairs up to the land¬ 
ing; then the back stair joins the main stair. 
Fig. 62 is the first-floor plan, and Fig. 63 the 
second-floor plan, of the same stairs. 



Fig. 66. Single-Light Window. Fig. 67. Two-Light Window. 

Where possible, put a coat closet under the 
stairs. This space cannot be utilized for any¬ 
thing but a basement stair or a closet. Usually 
there is a basement stair in the rear of the house. 

Fig. 64 shows an elevation of the stairway, 
giving all necessary information. 



Fig. 68. Fig. 69. 

Types of Window Construction. 


Windows. There are various types of win¬ 
dows used in the construction of buildings. The 
plainest is the single-light window shown in Fig. 
66. This is either pivoted, hinged, or fixed to 
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PLATE E —Architectural Drafting. 







ARCHITECTURAL DRAFTING 


289 


The windows are usually designated accord¬ 
ing to the number of panes of glass they contain, 
Fig. 67, for example, being a two-light window. 
Very often a large glass space is divided into 
smaller areas by means of horizontal and verti¬ 
cal strips called muntins, as shown in Fig. 68. 
The lower sash slides up, while the upper one 
is usually fixed in place; this upper sash is 
called a transom. 

When windows are grouped in twos or 
threes, they are separated by means of vertical 
divisions. These divisions are called mullions. 
The weights of the sash usually travel in these 
(see Fig. 69). 

The sash is usually the movable frame that 
contains the glass. A double-hung window is 
one in which the sash are counterbalanced by 
iron weights so that the sash will slide easily 
up and down in grooves in the frame. The sash 
of a window may be hinged to open like doors, 
in which case the window is called a casement 
window. If the sash are hung on pivots, either 
vertically or horizontally, we speak of the win¬ 
dow as a pivoted window. 

Referring to Fig. 68, A is the lower rail of 
the sash, usually from 2 y 2 to 3 inches wide; B 
is the meeting rail, from 1 to 2 inches wide; 
C is the stile, usually 2 inches wide; D is the 
upper rail, of the same width as the stile; E 
indicates the muntins, which divide the sash 
into small areas; F is the transom bar, or the 


290 


ARCHITECTURAL DRAFTING 



Jill 


Fig. 70. Typical Detail of Plank-Framed Basement Window. 

fixed bar between the transom G and the double- 
hung sash below. 

The usual thicknesses of sash are 1 y 8 inches 
for small windows, to 1%, 1%, and sometimes 
2^4 inches, depending upon the size of sash. 
The larger the window, the heavier the sash 
must necessarily be. 

In Fig. 70 we have a plank-framed window. 

This is the same kind of frame required for the 













































ARCHITECTURAL DRAFTING 


291 


casement window as shown in Fig. 76. Fig. 70 
is the typical detail for cellar window construc¬ 
tion. The windows usually have a single sash 
which may be divided by muntins into smaller 



Fig. 71. Double-Hung Window, Outside of Building Plastered. 

lights. Notice the projection on the bottom 
rail, which serves as a drip for all water coming 
from the glass. Such windows are usually hung 
at the side or top. Fig. 70 is detailed for a 















































































292 


ARCHITECTURAL DRAFTING 






Fig. 72. Double-Hung Window for a Erick Wall. 
























































































ARCHITECTURAL DRAFTING 


25)3 



Fig. 73. Part Section Showing Details of Bay Window Con¬ 
struction. 




Jettiom 

Fig. 74. Details for a Dormer or Roof Window. 


CENTER’LINE- 











































































294 


ARCHITECTURAL DRAFTING 



jEtCTION 

Fig. 75. Showing Details of Construction for Projecting Bay Window. 











































































































ARCHITECTURAL DRAFTING 


295 



Fig. 76. Details of Casement Window. 






























































29$ ARCHITECTURAL DRAFTING 

brick wall, although the same detail will apply 
to a frame wall. 

In Fig. 71 we have the details and dimen¬ 
sions for a double-hung window in a frame wall, 
the exterior of the wall being plastered. In Fig. 
72 we have the details for a double-hung win¬ 
dow in a brick wall. Notice that there is very 
little difference in construction. The parts of 
the construction are named for the sake of 
clearness, A being the sash, B the inside stop, 
0 the pulley stile, D the parting strip, E the 
outside casing, F the brick mould or staff-head, 
G- the back lining, H the sub-jamb, J the inside 
casing, K the stool, L the apron, M the ground, 
and N the sill. 

In Fig. 73 we have the construction for a 
bay window, showing the boxes, sash, etc. 

Fig. 74 shows the details for a dormer or 
roof window. 

Fig. 75 shows the construction for a pro¬ 
jecting bay window, the sash being hung to 
swing out. We have shown a half exterior 
view, a half interior view, and a section. 

Fig. 76 shows the details of a casement win¬ 
dow in which the head, mullion, and sill, with 
all adjoining construction, are shown. Notice 
the grounds or guide for the plaster work, as 
spoken of under “Lath and Plaster.” 

Fig. 77 shows the interior elevation of the 
door and window trim, with a large-scale draw¬ 
ing of the exact profiles of this trim. The trim, 
and in fact all interior woodwork, are fastened 


ARCHITECTURAL DRAFTING 


297 



BASt 


Fig. 77. Details of Window and Door Trim. 







































































298 


ARCHITECTURAL DRAFTING 


to the grounds, which are set to serve as guides 
for the plasterer, and which should be placed 
back of all interior finish. The base shown is 
the finish at the floor-line. The base is nailed 
to grounds; and the quarter-round mould at the 
floor is nailed to the floor, to cover the crack at 
the joining of the base and floor-line. 

SKETCHING 

In all architectural work, the art of sketch¬ 
ing is important. To be able to show one’s ideas 
clearly and artistically, or to reproduce some 
form or object in a pleasing manner, is indeed 
an essential qualification for the draftsman as 
well as the architect. Some have a natural 
ability to sketch, which lacks but the pencil and 
paper to give a true expression of the idea of 
the mind; while others acquire the art of 
sketching only by diligent study and persistent 
practice. Many instances have proven the fact 
that one may have ability, but that it needs 
developing, just as in the case of the mathema¬ 
tician, who becomes an expert in the higher 
mathematics by a gradual training from the 
simpler problems on up through more complex 
ones. Because one has not ability that is appar¬ 
ent at the outset, is no criterion whereby we 
may judge of his ability along any particular 
line. Learn to sketch, as it is a valuable asset 
for the architect. 

Fundamental Principle. To the beginner, 


ARCHITECTURAL DRAFTING 299 

the object usually presents itself as made up 
of small portions, and ordinarily he will make 
an attempt to show all the small details, over¬ 
looking the main mass or body of the object. 
The first thing is to be able to see the object 
as it really is, as it would really appear to the 
best advantage when sketched roughly and 
quickly. Learn to look at the general grouping 
of the different portions, and their relation to 
one another. The beginner attempts to draw 
the object as he sees it at close range, while the 
experienced person draws it as it appears at 
a distance. The tendency of the beginner is to 
represent everything with hard, sharp, and 
exact lines which are known from actual knowl¬ 
edge of the object to exist, although they do 
not really appear so. Learn to study the gen¬ 
eral proportions as expressed by the shadows, 
rather than by the exact outlines bounding each 
surface. Studying an object for sketching is 
really a study of the shadows. In all sketching, 
the proportion is the fundamental principle. 
Having correctly represented the proportions, 
then represent the object by means of the shad¬ 
ows as cast upon the object, and let the details 
be merely an after consideration. Learn to see 
the object correctly, and the representation by 
lines will come by practice. 

Pencils and Paper. The pencil is present on 
all occasions; therefore it is used a great deal 
in sketching. Pencils may be obtained in all 
degrees of hardness and softness. Drawing 


300 


AECHITECTUEAL DBAFTING 


pencils are usually denoted by H, HH, etc., for 
hard pencils, up to 8H, which is a very hard 
lead; the soft pencils are denoted by B, BB, 
etc., up to 4B for very soft pencils. An inter¬ 
mediate grade known as an HB is between the 
hard leads commencing with H and the soft 
leads commencing with B. This is a very con¬ 
venient grade to use for all kinds of work. A 
good drawing pencil should contain no grit. 

As a general rule, the larger the drawing, 
the softer the pencil, since the lead in the soft 
pencils is larger than that in the hard pencils. 
Therefore, it is rather difficult to make a small 
drawing with a really soft pencil. As stated 
above, the most satisfactory pencil for all- 
around work is the medium grade or the HB 
pencil. 

The pencil should never be sharpened to a 
point. Cut away the wood, leaving the lead its 
full size; and by a few strokes on a piece of 
scratch paper, wear off the sharp edge, until 
you have a line the full thickness of the lead. 

Hold the pencil comfortably between the 
fingers, not in a cramped position, but free and 
easy. The length of line, the position on the 
paper, and the width and intensity of the lines 
will determine just which movements of the 
fingers, wrist, or arm are the best suited to the 
work. In all work, avoid bending over the 
drawing; sit upright so that the drawing may 
be all seen at a glance, The paper should 


ARCHITECTURAL DRAFTING 


301 


always be at right angles to the line of sight, 
to insure the best work. 

The paper should have a somewhat rough 
texture for the best work, although some very 
pleasing sketches have been made upon smooth 
paper. Never use a glazed paper. The smooth 
paper requires greater care in its use, it being 
harder to erase anything successfully. A good 
grade of tracing paper makes a very good paper 
for sketches with a medium-soft pencil. 

Method. Begin sketching by drawing paral¬ 
lel lines horizontally; then make them vertical; 
then slanting lines—endeavoring all the time 
to make them all of the same width and 
intensity. After exercises in the drawing of 
straight lines, try circles and ellipses. Then 
sketch familiar household articles. From these, 
let the student take up more difficult work, 
learning to see objects as they actually appear 
to the e}^e, and not as they are really known to 
exist. 

Referring to Plates E and F, notice the 
method used for indicating surfaces. Instead 
of covering the side of the building with long, 
mechanical, parallel lines, the lines are made 
short, and broad, and break joint so as to give 
an uneven surface. The eaves are all repre¬ 
sented by the shadow they produce, there being 
no definite line for the edge of the roof. For 
the corners of the building, there is not a hard, 
sharp line, but a broken, irregular line. The 


302 ARCHITECTURAL DRAFTING 

doors and windows are all represented by the 
shadows they cast. 

It will be noticed that the shadow is the 
thing to reproduce. If the shadows are shown 
in their true relative proportions, in intensity 
and size, we are reasonably sure of a satisfac¬ 
tory sketch. For such work, the object is 



usually outlined with a light line, to get the 
proper lines and proportions; in other words, 
just enough lines are given to show the proper 
relation of dimensions. 

Having outlined the object, then commence 
with the soft, broad pencil, and indicate the 
texture and shadows by varying intensities of 
lines. 



















































ARCHITECTURAL DRAFTING 303 

Practice will give you the best training for 
developing the art of sketching. It is not 
enough to study work already done, analyzing 
lines and surfaces. Actual work and practice 
in drawing and sketching will do more for you 
than any mere study of sketches. 

Learn to make preliminary sketches quickly, 
and yet indicate general proportions and out¬ 
lines (see Pig. 78). This sketch was made in 
about five minutes’ time, while the architect 
was talking to his client. Some of the finer 
points of the original pencil sketch are neces¬ 
sarily lost in the pen-and-ink reproduction from 
which the cut was engraved. The figure repre¬ 
sents a possible treatment for a boiler house. 
This is a good example of a preliminary sketch, 
there being no particular time spent in the 
drawing and very few straight lines used, yet, 
when the sketch is studied, we can see the gen¬ 
eral effect that such a building would produce 
in sunlight. 

Make your sketches have some “snap” to 
them. Let each line be firm, starting and stop¬ 
ping in a way that shows it to be there for a 
definite purpose. Use plenty of free and easy 
lines, and also black lines. Do away with sharp 
lines, and never use hard pencils for this work. 

Por the purpose of laying out drawing, either 
for pencil, pen and ink, or pen-and-ink render¬ 
ing, a sketch will be shown to illustrate clearly 
the quickest and most satisfactory method. 
See Pig. 79, where the sketches are all rather 


304 


ARCHITECTURAL DRAFTING 



Fig. 79. Sheet of Drawings Laid Out with a Sense of Proportion. 






















































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ARCHITECTURAL DRAFTING 


305 


rough or uneven, but the general drawing shows 
the effect of proportions. The lines, instead of 
being long and continuous, are made up of 
short lines almost joining. 

PEN-AND INK RENDERING 

Finished drawings may be colored or ren¬ 
dered in a number of ways. The method of 
pen-and-ink rendering is very often used. It 
is indeed an accomplishment to be able to render 
in pen and ink successfully. This usually comes 
only from long and patient work in practicing. 
A drawing may also be rendered in pencil, or 
colored by means of water-colors. 

For pen-and-ink rendering, any black ink 
will do. A good grade of India ink is very 
satisfactory and convenient. There was a time 
when all drawing inks were made by grinding 
a stick of India ink in water on a stone bed; 
but now prepared inks are used almost entirely. 
The pens should be fairly large, and have a 
medium point; the tendency of beginners is to 
use too fine a point. Any good-quality tracing 
paper may be used. 

The outline of the work may be made upon 
scratch paper; and, by placing the tracing 
paper over it, the ink rendering can be made 
directly over the outline. Papers with soft sur¬ 
faces should be avoided, since the ink will have 
a tendency to spread, the points of the pen will 
often catch and spatter ink, and erasing is 


306 


ARCHITECTURAL DRAFTING 



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t-J !> 






















































ARCHITECTURAL DRAFTING 307 

almost impossible. Good bristol board makes 
a satisfactory surface to work upon. 

All lines should be firm and uniform, and 
series of parallel lines should give an even 
texture or appearance to a surface. Avoid the 
stiff, hair lines, which are too fine to give any 
character to the work. In making ink lines, 
while the general direction of the line may be 
straight, yet a line slightly wavy, or a line such 
as would be made by the trembling of the hand, 
is not objectionable. 

Use care in drawing lines to make them as 
uniform as possible, and exercise care in the 
starting and stopping of lines. Lines should 
naturally be a little heavier at the ending than 
at the beginning. 

Referring to Fig. 80, we see in this draw¬ 
ing, the general method of rendering a building 
in pen and ink. The window-panes, instead 
of being hard, sharp lines, are made by a series 
of parallel lines representing the shadow. 
Notice the treatment of the roof, the shadow 
of the cornice, and the general lines of the 
building. 

Fig. 81 shows the use of parallel lines en¬ 
tirely for the texture of the wall, and also for 
the shadows. 

Fig. 82 shows a very attractive drawing. 
Study the foliage around the house; see how 
it has been represented by lines, sometimes 
straight and sometimes curved. The distance 
to the background is obtained by the quality 



308 



















































309 


Courtesy of “Inland Architect and News Record. 

Fig. 82. A Well-Executed Example of Pen-and-ink Rendering. 















































































310 


AKCHITECTUKAL DRAFTING 


of the line; the further away the background, 
the lighter the line. Study the lines represent¬ 
ing the wall and roof surfaces. Notice that 
the lines in general are not straight, but are 
more or less irregular. The shadows in Figs. 
81 and 82 are composed of entirely different 
kinds of lines. Probably the best and easiest 
method is by the use of vertical lines. Notice, 
generally speaking, that there are no long lines. 
If it is necessary to make such a line, let it 
be represented by a series of short lines, with 
their ends almost touching. The tendency of 
the beginner is to make the rendering all too 
light. Put in some black, somewhere, as it 
makes the drawing more in contrast, and 
emphasizes other portions of the work. 

Plate G is a good example of a sketch ren¬ 
dered in pen and ink. 

WASH DRAWINGS 

Water-colors or India ink for coloring draw¬ 
ings, are used for the best work, almost entirely. 
By means of color or by the use of India ink 
for a monotone, the shades and shadows can 
be emphasized and the drawing made much 
more attractive. The usual method of proce¬ 
dure is to have the paper upon which the draw¬ 
ing is to be made, stretched tight upon a board; 
then cast the shadows, marking the outlines 
faintly with a hard pencil; then clean the 
drawing with a soft eraser; finally, have all 


ARCHITECTURAL DRAFTING 


311 


materials ready for applying the washes, and 
then start the color work. 

Materials. The usual materials for wash 
drawings are: the colors or the India ink; a 
number of brushes (one a bristle brush and the 
others soft camel-hair or Japanese brushes); 
plenty of receptacles for holding the color in its 
various shades, also one large receptacle for 
clean water. Porcelain or china dishes made 
especially for this work may be purchased from 
any dealer in artists’ materials. In addition to 
the above, a soft sponge and a number of blotters 
will be necessary. The paper should have a 
rough finish, as this takes the color or wash much 
better than paper with a smooth or glazed sur¬ 
face. Hot-pressed and cold-pressed papers of 
good quality are largely used for this work. The 
cold-pressed is a little rougher than the hot- 
pressed and is perhaps more frequently used. A 
good tracing paper may be used if the color is 
applied thick and in spots, or where no attempt 
at a true wash drawing is made. Care will have 
to be exercised in the use of tracing paper, as 
too much water will spoil the work. 

As mentioned above, the paper upon which 
the drawing is made has to be stretched tight on 
the drawing board. This may be done after the 
drawing has been made, although it will be 
found much more convenient to stretch the 
paper first, and then make the drawing. To 
stretch the paper, it should be thoroughly 
wetted all over, and kept wet until it is firmly 


312 


ARCHITECTURAL DRAFTING 


fastened in place; this wetting causes the paper 
to expand. On the four edges of the paper, for 
about an inch back from the edge all around, 
place glue or drawing-board paste. The paper, 
being expanded by the water, should now be 
fastened or pressed down onto the board, work¬ 
ing opposite edges at the same time. Do not 
attempt to stretch the paper perfectly tight. 
Be careful to see that the edges of the paper are 
in contact with the board, and run the back edge 
of a pocket-knife all around, to insure the glue 
or paste on the edge of the paper coming into 
contact with the board. 

After the paper is thus stretched, take all sur¬ 
plus water off by means of a sponge, and dry the 
paper as much as possible with the sponge. 
Allow the paper to stand until thoroughly dry, 
when it will be found that the paper has 
shrunken tight and smooth, giving a good sur¬ 
face for the drawing, and the rendering will be 
much easier because the paper is held firmly in 
place. Be very careful to see that the paper is 
stuck to the board all along each of the four 
edges, before allowing the paper to dry. 

After the drawing has been made, the 
shadows are cast with light pencil lines. Clean 
the drawing with a soft eraser, either of 
kneaded rubber or of “sponge” rubber. These 
erasers remove the general surface dirt without 
affecting the lines materially. 

The use of an India ink wash will be 
described, although the same treatment wiU be 


ARCHITECTURAL DRAFTING 


313 


true of colors. The drawing should, of course, 
be inked very carefully before any tinting is 
started. The erasing of lines should be done 
very carefully as the surface of the paper, if 
rubbed too hard, will be abraded—so that when 
colors are applied they will soak in instead of 
remaining on the surface. The drawing may be 
very carefully washed after the inking is com¬ 
pleted, with a soft sponge; this removes surplus 
ink and leaves the lines more subdued. 

Method of Applying Wash. Having the 
drawing all ready to render, a few principles 
must be followed to insure the best results. 
Have your water, color, brushes, blotters, and 
sponge, all handy; have plenty of clean water 
convenient; for heavy or dark shades, apply sev¬ 
eral washes of a lighter value, instead of putting 
the heavy color on all at once. 

Having once started the wash, carry it on 
continuously, without allowing it to dry; any 
mistakes can be remedied after the wash is com¬ 
pleted, but the wash should never be interrupted 
to rectify mistakes. Lighten the wash by the 
gradual addition of clean water; be careful to 
take the color from the top of the dish, to avoid 
getting the sediment. Always take about the 
same amount on the brush, and do not allow the 
brush to become too dry before adding more, as 
this will dry much quicker on the paper, and the 
addition of more will cause a streaked or 
mottled effect. 

Having reached the bottom of the drawing, 


314 ARCHITECTURAL DRAFTING 

take up any standing water or color with a 
blotter, as it will make a bad appearance if this 
is all allowed to stand and dry. The board 
should be tilted slightly, so that the wash will 
have a tendency to move downward; and it 
should be left in this position until the color is 
dry. Do not attempt to patch or add color to 
any portion of the drawing that has commenced 
to dry. 

Having put into a saucer enough of the ink 
for the drawing, apply the brush to the surface 
of the ink, soaking up a brushful. If the draw¬ 
ing is of any considerable size, a wide, flat brush 
of carneTs hair can be used to better advantage 
than a pointed brush. The pointed brush, how¬ 
ever, will be the one most used on ordinary-sized 
drawings. 

With the brush filled with the ink, apply to 
the upper edge of the drawing, carrying it 
across the top and gradually working it down¬ 
ward, adding more ink as the brush becomes 
drier. Since all work is darker at the top and 
gradually shades lighter, as the wash is carried 
down the sheet, add a little clean water each 
time, until, at the bottom or last application of 
the brush, it should contain almost clear water. 
This shading from darker at the top to lighter 
at the bottom is a conventional way of rendering 
plans. 

Plate H (lower figure), shows a plan 
rendered in this way, the darker effect being 


ARCHITECTURAL DRAFTING 


315 


obtained by a series of light washes and not by 
a single wash. 

The brush is held in much the same way as 
a pencil, the hand being entirely free from the 
paper, or perhaps at times resting on the little 
finger. 

In case of any blotches or other objection¬ 
able portions, these can be remedied with a little 
care. Take the sponge and dip it into clear 
water. Sop the portion thoroughly, allowing 
enough time for the water to soak into the color; 
then apply a clean blotter, and soak up the 
water. Be very careful not to rub the blotter 
over the surface. If very carefully done, the 
trouble can be remedied, and the drawing will 
scarcely show the spot. 

Be careful, in all work, not to allow dust or 
hairs from the brushes to remain on the draw¬ 
ing. These may be removed with a toothpick, 
by slightly moistening the end of the toothpick 
in the mouth and carefully lifting the objects off 
the drawing. For lines that have overrun after 
the wash has become dry, take the bristle brush, 
moisten it in clean water, and rub gently over 
the color outside the line. When the water has 
soaked into the color, use the blotter. The 
trouble can be remedied by one or two such 
treatments. 

The methods of procedure described above 
concern the application of flat washes. 

It will take considerable practice to render 
well. The beginner is advised to make several 


316 


ARCHITECTURAL DRAFTING 


sheets of such work as described above, before 
attempting a plan or elevation. Use the washes 
on the elevations to show shadows, or the por¬ 
tions in shade. See Plate H (upper figure), 
which shows an elevation rendered in the 
conventional way. 

Water-colors are applied or “floated on” in 
the same manner as the India ink washes. Re¬ 
member that in the use of colors you will have 
to be very careful to have a dish and a brush 
for each color, as the least i>article of color in the 
clear water will sometimes change the color of 
some other dish if the two are used. Clean color 
boxes, brushes, and water are the first requisites 
of good rendering in color. 

Colors may be obtained either in tubes, sim¬ 
ilar to oil paints, or in pans, which are small 
dishes of color. These should all be kept in a 
water-color box. There are usually two palettes 
or lids to this box, on which the colors may be 
mixed. If there is to be any quantity of color 
used, these palettes will not be large enough, 
and the dishes should be used. 

In the use of either color or India ink, apply 
enough color to give the drawing some char¬ 
acter; make it 44 snap;” do not commit the oft- 
repeated offense of having your drawing look 
“sickly” or have a washed-out appearance. 
Attack the problem of rendering, with determi¬ 
nation; put on the colors as colors, and not as if 
you were afraid of spoiling something. 

Red, blue, and yellow are commonly called 


AECHITECTTJEAL DEAFTING 317 

the three primary colors, and in combination 
will give the intervening tints or colors of the 
prism. Thus blue and yellow will give green; 
red and yellow will give orange, and red and 
blue will give violet or purple, the tints varying 
according as one or the other color predominates 
in the combination. 

ORDERS OF ARCHITECTURE 

In the study of architectural history, we turn 
to the Greeks and Romans for a great many 
fundamental principles of design. We see that 
they had proportions for everything. Adopting 
some unit, the building was designed and 
erected with this as a unit. They had certain 
arrangements of a cornice, a column, and a 
base which have been handed down for ages. 
All of the parts had certain relations to one an¬ 
other in size. This combination we have called 
an Order. 

We have four Orders which are used in archi¬ 
tecture—the Tuscan, Doric, Ionic, and Cor¬ 
inthian. (See Pigs. 83 to 86.) A fifth Order— 
the so-called Composite Order —combines fea¬ 
tures of the others. 

It will be noticed that all the ornamentation 
on the mouldings has been omitted for the sake 
of clearness in revealing the important propor¬ 
tions. Each Order has the three main divisions 
—the entablature, column, and pedestal. In our 
architectural design, the base or pedestal is 


318 ARCHITECTURAL DRAFTING 



6 *CORNlCB 
3 • FRIEZE. 

* ARCH IT RAVE 
3 • CAP. 

£ • BASE. 

I * PLINTH 



Fig. 83. The Tuscan Order. 











































































































AECHITECTUEAL DEAFTING 319 

usually omitted. As will be seen from the 
drawings, the entablature has three divisions— 
the cornice, frieze, and architrave; the column 
is divided into the cap, shaft, and base; the 
pedestal, into the cap, die, and base. 

The entablature varies from 1 % to 2 y 2 times 
the diameter of the column. The cornice pro¬ 
jects from the face of the column a distance 
equal to the height of the cornice in all cases 
except in the Doric Order. The frieze is a flat 
band or surface, sometimes ornamented. The 
architrave may be made of a single band, or it 
may be divided into a number of bands. 

The column has a capital or top, varying 
from a plain cushion to the elaborate cap of the 
Corinthian and Composite Orders. The shaft, 
in some Orders, is perfectly plain, while in 
others it is fluted. All columns have a taper at 
the top. The shaft is carried up straight for 
one-third the height; and from this point it 
tapers. This tapering is called entasis. The 
shaft rests on a base which consists of a torus 
and a plinth, or a series of toruses called an 
Attic base. 

The diameter of the column at the straight 
portion is used as the unit of measurement for 
all other parts. 

Fig. 83 shows the Tuscan Order, with the 
principal proportions. This is the simplest 
Order, being perfectly plain. It is used a great 
deal for porches, or for lower stories where there 
are a series of Orders above. 


330 


ARCHITECTURAL DRAFTING 







































































































. 






























. 


































- 







* 








PLATE G —Architectural Drafting, 













































ARCHITECTURAL DRAFTING 


321 



Fig. 85. The Ionic Order. 

















































































323 ARCHITECTURAL DRAFTING 

Fig. 84 shows the Doric Order. This has 
a great deal of ornament, both on the soffit of 
the corona (the projecting, crowning member of 
the cornice), and on the mouldings. In most 
modern designs, we see this Order modified 
more or less. 

There are two types of cornices used with 
the Doric Order—one with the mutules (project¬ 
ing flat blocks ornamented on the under sur¬ 
face) ; and the other with the dentils (a course of 
small cubes in the bed-moulding). The general 
profile of the cornice is different in the two 
types. The shaft is very often fluted. 

Fig. 85 shows the Ionic Order, with the prin¬ 
cipal proportions. The cornice may have 
brackets called modillions, or it may have the 
dentils. The capital for the column varies, the 
left-hand half showing the cushion capital, and 
the right half shows the volute turned at 45 
degrees, thus giving all faces alike. The shaft 
is fluted, and the mouldings are usually 
ornamented. 

Fig. 86 shows the Corinthian Order. The 

main difference from the other Orders is the 
capital, which is highly ornamented by means 
of acanthus leaves. This Order is probably the 
most dignified, and is also the most expensive. 
Sometimes the shaft is fluted. The mouldings 
are all greatly ornamented. 

There is a variation of the Corinthian 
Order, called the Composite Order, already re¬ 
ferred to. The chief difference is in the volutes 


ARCHITECTURAL DRAFTING 


323 



Fig. 86. The Corinthian Order, 


STRAIGHT 











































































OVOIO 0R3OWTEL 


ELLIPTICAL OVOLO 


CAVELTTO 



TORUS OR BEAD 



FILLET OR lISTEL 



CONGE 



3 / 4 - POUND BEAK MOULDING SPLAT-FACE, BEVEL OR CHAMFER 





SUNK <«N o Raided FU.L6T SCOTIA 




THUMB MOULDING 


CYMA EECTA CYMA REVERSA 




QUIRKED CYMA 



REEDING 


Fig. 87. Common Forms of Classic Mouldings. 


324 










































































ARCHITECTURAL DRAFTING 325 

of the capital, they being much larger and 
turned out the same way as in the true 
Corinthian. 

All of these Orders are modified to a greater 
or less degree in all applications of them, each 
architect making changes to conform to general 
styles he is using on the building. The propor¬ 
tions, however, cannot be varied much without 
spoiling the general effect of the Order. 

Fig. 87 gives some of the common forms of 
mouldings, with the corresponding names. 

ARCHITECTURAL LETTERING 

Good lettering is an essential requisite of a 
good set of plans. A drawing poorly executed 
but lettered attractively and well, will look a 
great deal better than one which is well drawn 
but which is poorly lettered. Therefore, at the 
start, let it be said that a draftsman needs to be 
a good letterer as well as a good draftsman. 

We find lettering used with the earliest art 
of the Egyptians. These ancient people ex¬ 
pressed their thoughts by means of symbols, 
more or less geometrical in outline. These in¬ 
scriptions we find in the oldest of our Biblical 
writings; they were worked in stone and written 
on their papyrus. The forms used are called 
hieroglyphics, and students of ancient languages 
have been able to translate these strange 
characters. 

The Greeks and Romans had characters very 


326 


ARCHITECTURAL DRAFTING 


similar to ours. We have copied their forms, 
and use them to-day for our letters. Some of 
the inscriptions on the ancient Greek and 
Roman temples are splendid examples of letter¬ 
ing, as to both form and spacing. 

The first principle to remember is that good 
lettering comes from freehand work, and not a 
mechanical product. The tendency of the begin¬ 
ner, especially, is to make all letters by means 
of straight edges and drawing instruments. 
The difference in the two methods is evident 
when we compare work of the two kinds. The 
printed letter such as is used for newspaper 
headlines, and the title as executed on a set of 
drawings, show very clearly that the former is 
too mechanical and stiff, w T hile the latter, if well 
executed, is much the more attractive. Then 
again, freehand lettering can be adjusted to the 
general type of the drawing. 

After the graceful ease and ready adapta¬ 
bility of freehand work, the next requisite in 
good achitectural lettering is simplicity. The 
simpler the letter, the easier made, and the 
better the general effect. Examples illustrating 
this can be seen in the effect of highly orna¬ 
mental letters in newspaper advertising. 

Learn to make the titles the same as a free¬ 
hand sketch. Make plenty of strokes of the 
pencil; get the general shape of the letters, and 
the spacing. Do not attempt to make each letter 
with one stroke of the pencil. 

After having made the title with several out- 


ARCHITECTURAL DRAFTING 


327 


lines, then go over this, and the final lettering 
can be done from this sketch of the letters. Get 
the general proportions and shapes first, to¬ 
gether with the spacing, before trying to get a 
finished title. Develop the title as a whole, and 
let the small details of each letter be the last 
thing attempted. 

The effect of the spacing of letters upon the 
general appearance of the title, will be seen 
from the accompanying illustrations of ex¬ 
amples. Study the available space for the title; 



and make the size, style, and spacing of the 
letters to suit the conditions. The guide lines, 
with perhaps a few lines limiting the edges of 
the letters, are the only mechanical lines that 
should be used. 

It will be well to consider some of the letter 
forms, in order to understand just how they are 
made to look the best. See Fig. 88. The A is 
made wide enough at the bottom to give the 
appearance of stability. The cross-line should 
always be below the center, for, if exactly on 
the center, the upper portion appears too small 
for the base. The B should have the upper half 



328 


ARCHITECTURAL DRAFTING 


smaller than the lower, both as to the width and 
the cross-line. It appears over-balanced if the 
upper half is made exactly like the lower half. 
The C should have the upper projection of the 
curve a little less than the lower. E should be 
smaller above the center line than below. The 
cross-line of P, H, and R should be the same. 
G should be similar to C in the greater projec¬ 
tion of the lower part of the curve. P, because 
it has no lower portion, should be made a little 
larger than one-half the height. S should have 
the upper half the smaller. X and Y usually 
have their intersection on the center line. 

By keeping these facts in mind, the appear¬ 
ance of the letters will be much improved. 

For different styles of titles, where certain 
types of letters are used, the above rules will 
be modified; but for general work they should 
be followed. 

Single-line letters are used almost entirely in 
lettering plans and drawings. 

Spacing of Letters. As to the spacing, there 
is no set rule for standard dimensions; but a few 
rules may be given as a guide. Letters which 
have vertical and parallel sides coming together, 
are spaced the greatest distance apart. Take II 
and B, for example; these require the largest 
space. In case of a curve, as an 0 or a C, with 
an N or an II, the spacing will be about two- 
thirds of that for the H and the N. This same 
rule will hold for the curve of a D with an N or 
M or any letter with a vertical line. 


ARCHITECTURAL DRAFTING 329 

If two curves come together—as, for ex¬ 
ample, a C and a G, or a B and a C—the space 
is slightly less than for N and 0. 

If A and V come together, make the lower 
point of the A come directly under the upper 
point of the V; there should be no vertical space 
between these letters. A or Y, with 0 or B, 
will have about the same spacing as two curves, 
such as B and C or C and 0. 

While the above rules are only general, yet 
they will serve as a guide. 

When marks of punctuation are used, the 
spacing will have to be increased over that of 
the regular arrangement. The spacing between 
words depends upon the style of letter used and 
the available space. Increasing the spacing will 
make the words more prominent. 

In doing all letter work, it should first be 
penciled completely, before any inking is done. 
It is much easier to erase and make changes 
while the title is still in pencil than after it is 
inked. The ink will emphasize all irregularities. 

The tendency of the beginner is to use too 
fine a pen. A new pen is always hard to work 
with, since it makes a thin hair line. Sometimes 
a new pen can be made to work more easily, by 
heating the point with a match. This will 
render it more flexible, although the pen will 
not last so long. Be very careful to make the 
same thickness of line for all parts of the letters, 
and for all letters of the title. It will require 
practice to be able to use the pen satisfactorily. 


330 


ARCHITECTURAL DRAFTING 


The inks can be any of the ready-mixed 
India inks. These are very satisfactory, and are 
much more convenient than grinding the ink 
from an India ink stick. Since the prepared 
inks evaporate and therefore thicken when ex¬ 
posed to the air, the cork of the bottle should 
always be at once replaced after filling the pen. 
Some grades of black writing ink may be 
used, although the India ink is much more 
satisfactory. 

Almost all of the drawing papers will take 
ink. Tracing paper and tracing cloth are used 
a great deal. Bristol board is used where letter¬ 
ing is employed, as for an inscription, or 
where it is not a part of a drawing. 

In lettering, first rule the guide-lines in 
pencil; then pencil the letters, and then ink. 
There is no rule for holding the pen; be sure to 
learn to have a free and easy stroke. By 
practice, learn to have a uniform line; and have 
confidence in your ability before you start. 
Usually the beginner is a little backward when 
starting the lettering on a sheet. By practicing 
vertical lines, inclined lines, and curves, one 
gradually learns the use of the pen. It should be 
noted that the strokes are all downward; and 
a curve, as for 0, is made up of a series of 
strokes. There will be difficulty in getting 
straight lines and curves of the same size. 

In penciling, always use a soft pencil, one 
free from grit. Make the lines as light as pos¬ 
sible, so that they can be erased with as little 


ARCHITECTURAL DRAFTING 331 

pressure as possible. Keep the paper as free 
from erased lines as possible, as the erasing 
tends to destroy the general surface of the 
paper, and makes it much more difficult to ink 
properly upon it. Should a mistake be made, 
after the ink has become thoroughly dry, use 
an ordinary pencil eraser, and rub gently in all 
directions. Stop at short intervals to allow the 
eraser to cool, as it will smear the ink if it 
becomes too hot from rubbing. After the eras¬ 
ing, take some smooth, hard surface—be sure it 
is clean—and rub gently over the erased surface 
to give a smooth finish to the paper. Some 
think that a regular ink eraser is necessary to 
remove the ink; but the pencil eraser will do the 
work better and leave the surface of the paper 
in much better condition. The work of erasing 
will be slow and tedious, but it should be care¬ 
fully done. 

The size of letter will depend upon the space, 
if the space is limited. Otherwise the letter 
should be made to correspond to the size of the 
drawing, a large, full-size drawing requiring a 
large letter, while a quarter-inch scale drawing 
will require a small letter. By a careful study of 
proportions, one can make a drawing look the 
best. Poor judgment in this respect will often 
spoil a well-drawn plan. 

Titles are put on ever}^ sheet of a set of draw¬ 
ings. Each drawing on the sheet must have a 
single-line title; and each sheet must have a title 
complete, giving the name of the work, the 


332 


ARCHITECTURAL DRAFTING 


client’s name, the location, the scale, and some¬ 
times the date. For the convenience of the 
architect, he usually places in one corner his 
name, the number of the sheet, the job number, 
the initials of the different men who made the 
drawing, and the date. This gives him his 
record for filing the set of drawings. 

Choose a style of letter that will be clear and 
simple. While the architect has more liberty in 
the choice and spacing of letters than the 
engineer, yet the fundamental principle is clear¬ 
ness. Capitals are used almost entirely for 
titles, and small letters for notes of all kinds. 


The Kactor.i> A wLh \te ctural Co- 

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Fig. 89. Method of Centering a Title. 


In laying out a title, there is usually a cer¬ 
tain space it will have to occupy; therefore the 
title must be centered about a vertical center 
line through this space. The method of center¬ 
ing a title is shown in Fig. 89. Decide upon the 
wording, and write out each line as it is to be 
copied. Upon a piece of scratch-paper, spell out 




ARCHITECTURAL DRAFTING 333 

the letters in each line, numbering each letter in 
order, and also the spaces between the letters. 
The center of each line is then evident. 

Lay out the center line of the space to be 
occupied on the drawing, and, after drawing the 
guide-lines, start at the center line, and com¬ 
mence sketching in the letters, first to the right, 
as shown in the third line, Fig. 89. Thus the 
right half of the title is sketched first. Now 
take a piece of paper, and lay off to the left the 
same distance as the right half extends to the 
right. This gives us a starting point for the 
left half. This part may be worked either from 
the left to the right, or, as shown in the fifth 
line, the letters may be placed in the order as 

•Interior Details- 

•Residence.• fojs. Hom- A-.5-Pe.ape.r- 

■Albany - - - We.w York* 
•Ja 5-M'WH!TIL £ 5tTHJ.TE.MPLE- 
* Associated Architects • 

- Vfbana - Illinois* 

Fig. 90. Arrangement of a Title Showing Symmetry hut not 
Mechanical Stiffness. 

numbered. A little experience will enable one 
to lay out a title quickly and accurately in this 
manner. 

Having the general arrangement in pencil, 
go over it carefully, and make the letters, 
properly spaced and in good outline. The title 
is then ready for inking. In all titles, let the 
composition or spacing be such that while the 
title as a whole shall be symmetrical, its general 


334 


ARCHITECTURAL DRAFTING 


ARCHITECTURAL 

• LCTITRU- 

TO 12. 

TITLEC^-OHEETA 

abcdef^hij klron 

* opcjrsf uuvaxyz- 
Convenient for all notes 

on Scale Drawings* 

ADCDUrGMIJ 

KLMN0PQR5T 

-UVWXYZ.- 

• locale incVi- i foof* 

Fig. 91. Easily-Made Letters for General Drawings. 






ARCHITECTURAL DRAFTING 


335 


ALCHITCCTUm 

LLTT1RJ 

abcdcf^hijklinrtn 

opcjn/iuvwxyz. 

A good letter for 

Inj'cri'pdom and 

General nolej-'A 
Dignified leti cr 

ABCDETGfllJK 
LMNOPQAJTV 
YWXYZ— 

-Front ellvation- 

Fig. 92. A Dignified Type of Letter for Inscriptions, General 
Notes, etc. 


336 


ARCHITECTURAL DRAFTING 


ARCHITECTURAL 

LETTERS 

A&CDE.FSH IJK.LM.NO 
pgl&stvvwxya- 


ADCDEf&HUKLMNO 
PG.&5TWWYYZ■ £ 

ABCJDEF GH1JKJL 
MNOPQ.RSTW 
—WXYZ - 
- ELEVATION - 

-.SCALE fl NCH ' 

Fig. 93. Showing Double-Line Letters Used Largely for General 
Titles. 




DESIGN OF A COURT HOUSE FOR A SMALL CITY. 



Courtesy of Armour Institute of Technology. 

ELEVATION AND PLAN RENDERED IN WASH. 


PLATE H—Architectural Drafting. 




























ARCHITECTUKAL DRAFTING 


337 


ARCH 1 TtCTURAL 
LLTTLRA 
DIAdFAH "rA-y-CORim 
APCDnrq/H!j k 
L/Yi°fo-K^T 
V V/XYZ • A<3°°p 
LETTE.R r°K 
IAR(4RDRAV!HCC 
mKL ALL LjHD 
P R EXA4RD * 
1234567390 - 

Fig. 94. Letters Suitable for Large-Scale and Full-Sized Details. 


*QErL.A-nvE:Ofzn:-or• Letteteinq poe E^awimq^* 




’$v§ 



r*> 


338 


Fig. 95. Sheet Showing Relative Sizes of Letters to Use on a Drawing. 



ARCHITECTURAL DRAFTING 389 

♦ 

ARCHITECTURAL 

LETTERS 

A GOOD STYLE or 
LETTER™ NULL 
SHE DETAILS 

<3bccT^/^l?ijJc!mnop^rsi 

uvwxyz. - /Z345G7&90- 

DETAIL 3 or EOOK 
CASE - NOTE-Mm 

gj] doors io slide. -—=- 


Fig. 96. A Good Form of Slanting Letter for Large Work and 
Full-Sized Details. 




340 


ARCHITECTURAL DRAFTING 


outline shall not be inclosed by straight lines. 
A line, for example, connecting the ends of the 
different lines of a title should not be straight, 
but irregular, as shown in Fig. 90. Try to avoid 
making the lines exactly the same length. 
Where the same general title is to be used on a 
number of drawings of a set, it is very con¬ 
venient to make the title in pencil on a piece of 
paper, and trace it through the tracing cloth 
for the finished drawing. This saves a great 
deal of time, and gives a uniform title for every 
sheet. 

The styles of letters mostly in use by archi¬ 
tects are shown in Figs. 91 to 96. 

Fig. 91 presents an easy substantial title, 
quickly made, and very clear. This form of 
letter will be found very satisfactory for general 
drawings. 

Fig. 92 shows a type of letter largely used. 
It has a dignified appearance, is suitable espe¬ 
cially for inscriptions on tablets or buildings, 
and is quickly and easily made. 

Fig. 93 shows a form of double-line letter, 
very quickly made; this letter is used largely for 
general titles. 

Fig. 94 shows a good style of letter to use on 
full-sized details and large-scale details. It is 
made by several strokes of the pen. Long lines 
are hard to make; therefore the long lines are 
made up of a series of short lines. When well 
done, it makes a very attractive form of letter 
to use. The figure is small, and the true values 


ARCHITECTURAL DRAFTING 341 

of the broken lines do not show up as they do 
on large work. 

Fig. 95 is a sheet showing the relative sizes 
of letters to use on a drawing. The small letters 
may he made either slanting or vertical. 

It is much easier to make a slanting line than 
a vertical line. Irregularities show less in slant¬ 
ing letters than in vertical letters, and for 
this reason some architects use a slanting letter 
entirely. The vertical letter, however, is much 
more dignified, and, when well done, is more 
satisfactory. 

Fig. 96 is a good form of slanting letter for 
full-size detailing and large work. 

It is as true of drafting as it is of every other 
branch of worthy human endeavor .' Experience 
is the one great and indispensable teacher. Just 
as we learn to sing by singing, and to build 
houses by building them, so we learn to draw 
by drawing; and it is only by persistent 
practice on the part of the draftsman that the 
highest proficiency can be acquired. 




INDEX 


Mechanical Drafting 


A 

PAGE 

Alternate Spaces. 186 

Angle, To Bisect an. 34 

Angles.178 

Approximate Developments.. 118 

Approximations. 43 

Arch. 140 

Architect’s Scale.11, 19 

Assembly Drawings. 147 

Auxiliary Planes. 101 

Auxiliary Planes of Projec¬ 
tion. 78 

Axes, Isometric. 128 

B 

Beam Compass. 5 

Beams. 178 

Bisecting an Angle. 34 

Bisecting a Straight Line.. 33 

Blue-Prints.152, 154 

Board, Drawing. 7 

Bolts. 180 

Dimensioning of. 158 

Border Line, Laying Out... 19 

Bow Pen. 22 

Bow Pencil.4, 22 

Bow Spacers.4, 22 

Building Construction, 

Working Drawings for... 166 
Built-Up Members. 178 

C 

Cabinet Projection. 137 

Cavalier Projection. 137 

Center Line. 149 

Channels.5, 178 

Circle, Circumscribing about 

a Triangle. 38 

To Inscribe in a Triangle 39 

Circles, Shading of. 151 

Clearness. 148 

Columns. 178 

Compass.4, 19 

Beam. 21 

Small. 22 

To Ink with... 25 


PAGE 

Cone, Isometric of a. 136 

Co-ordinate Planes. 50 

Cross-Hatching . 160 

Curved Lines, Isometric of. 133 
Curved Surfaces, Intersec¬ 
tion of. 115 

Curves, Irregular or 

French .10, 22 

Cylinder 

Development of the. 117 

Isometric of Vertical. 135 

D 

Detail Drawings. 147 

Details of a Vertical Post. . 185 

Development . 86 

Developments, Approximate. 118 
Development of the Cylinder 117 

Dimensioning. 155 

Dimensions, Distribution of. 158 

Dividers . 4 

Hair-Spring . 21 

Dotted Line. 149 

Drafting, Practical. 145 

Draftsman’s Outfit. 2 

Drawing Board. 7 

How to Use. 15 

Drawing, Beading a. 70 

Drawings 

Assembly. 147 

Detail .147 

Preliminary . 147 

W T orking . 147 

Drawing to Scale. 19 

Duplication of Parts. 159 

E 

Elevations . 51 

Ellipse; Problems.41, 42 

Erasers . 11 

Extension Lines. 156 

F 

Field Biveting. 180 

Finished Surfaces..... 159 

343 

































































344 


INDEX 


G 


PAGE 

French Curves.10, 22 

Geometrical Problems. 33 

Girders . 178 

Ground Line. 50 


PAGE 

Lines —Continued 

Projection of Oblique.... 59 
Shade. 150 

M 


H 


Micrometer Screw. 6 


Hair-Spring Dividers.4, 21 

Hexagon; Problems. 40 

Hexagon, To Construct a... 30 

I 


O 


Oblique Projection. 137 

Orthographic Projection... . 50 

Outfit. 2 


Inclined Lines, Drawing.... 16 


Ink, Drawing. 12 

Inking.23, 32 

Instruments 

How to Use. 15 

Illustrated . 3 

Testing . 13 

Intersection . 86 

Intersection and Develop¬ 
ment . 86 

Essential Principles. 119 

Intersection of Solids. 104 

Irregular Curves.10, 22 

Isometric Axes. 128 

Isometric Drawing. . ...126 

Isometric of Curved Lines.. 133 

K 

Kinds of Lines. 148 

L 

Lengthening Bar.4, 21 

Lettering . 163 

Line 

Center . 149 

Construction . 149 

Dimension. 149 

Dotted. 149 

Full . 149 

Ground . 50 

To Bisect a. 33 

To Divide into Equal Parts 37 
Lines 

Drawing Vertical or In¬ 
clined . 16 

Kinds of. 148 

Non-Isometric . 130 

Oblique f ,.. ,. 55 


P 

Paper 

Detail . 12 

Duplex. 12 

White Bond. 12 

Cold-Pressed. 12 

Hot-Pressed . 12 

Normal . 13 

Bristol Board. 13 

Parallels, To Draw. 36 

Pen 

Bow. 22 

To Sharpen. 27 

Pencils .12, 19 

Penciling and Inking. 27 

Perpendicular, to Draw a... 35 

Perpendicular Lines, Draw¬ 
ing . 17 

Pictorial Drawing.. 126 

Planes 

Auxiliary .101 

Auxiliary, of Projection.. 78 

Co-ordinate. 50 

Co-ordinate Seen Edgewise 53 

Intersection of. % .... 86 

Planes of Projection....... 50 

Planes, Profile. 64 

Plates . 178 

Plans and Elevations. 51 

Practical Drafting. 145 

Practical Problems. 120 

Preliminary Drawings.147 

Pricker. 11 

Prism, Development of the.. 107 

Profile Planes. 64 

Projection. 49 

Auxiliary Planes of. 78 

Exercises in. 81 

Important Principles. 80 

Oblique . 136 





































































INDEX 


345 


Pro j ection —Continued 

PAGE 


PAGE 


Spaces, Alternate. 


Planes of. 

50 

Spacing. 


Third Angle. 

66 

Spiral of Archimedes. 

. 45 

Third Plane of. 

64 

Spirals . 


Projection of Oblique Lines. 

59 

Structural Drafting. 

. 176 

Projections, Actual. 

52 

Surfaces, Finished. 

. 159 

Protractor. 

6 

i 

T 

Q 


T-Square . 


Quadrants. 

51 

How to Use. 



Testing . 


E 


Testing Instruments. 

. 13 

Reading a Drawing. 


Third-Angle Projection... . 

. 66 

71 

Thumb-Tacks . 

7 

Rivets and Bolts. 

180 

Tracing Cloth. 

. 13 

Ruling Pen. 

5 

Tracing, The. 


To Ink with. 

24 

Triangles . 




How to Use. 


S 


Problem . 


Scales . 

10 

Testing . 


Scale, Architect's. 

11 

TT 


Screw, Micrometer. 

6 

V 


Sections . 

160 

Vertical Lines, Drawing. .. 

. 16 

Shade Lines. 

150 

Vertical Post, Details of a. 

. 185 

Examples of. 

150 



How Used. 

150 

W 


Shading of Circles. 

Shop Riveting. 

Sketches . 

151 

180 

147 

Working Drawings. 

Working Edge. 

. 147 

Slope . 

58 

7 


Solids, Intersection of. 

104 

4i 


Solid Members. 

178 

Z-Bars. 



y 














































1 


















I 









I 








V 


4 























INDEX 


Architectural Drafting 


A 

PAGE 

Aligraphy. 240 

Apron . 296 

Architecture, Colonial. 2i9 

Architectural Drafting. 187 

Architectural Drawings..... 194 

Architectural Forms. 244 

Architectural Lettering.325 

Architrave . 217 

B 

Back-Lining. 296 

Balusters. 285 

Base. 217 

Bay Window. 296 

Blue-Printing. 238 

Box Cornice. 268 

Brackets . 269 

Brick Moulds.296 

Buildings, Types of. 220 

Building Lines. 249 

Built-Up Doors. 279 


PAGE 

Counter-Flashing. 276 

Crown-Mould . 269 

D 

Deadening Material.. 273 

Dentil Course. 269 

Details of Construction.268 

Die. 217 

Dimension Lines. 249 

Doric Order. 317 

Dormer Windows. 296 

Doors. 279 

Built-Up . 279 

Stock . 279 

Double-Hung Windows. 289 

Drawings 

Architectural . 194 

Competition .. 203 

Reproducing. 238 

Wash . 310 

Working . 206 


c 


E 




Elevation, The. 

. 216 

Cap. 

217 

Elevations, Treatment of.. 

. 221 

Capital. 

217 

Entablature. 

. 217 

Carriages . 

285 



Casing 


F 


Inside . 

296 



Outside . 

296 

Fascia .. 

. 269 

Casement Windows. 

289 

Fireplaces. 


Colonial Architecture. .. 

219 

Flashing and Counter- 


Colors, Primary. 

317 

Flashing . 

..276 

Column . 

217 

Floor Construction. 

. 271 

Competition Drawings. 

203 

Deadening Material. 

. 273 

Composite Order. 

317 

Under-Floor .. 

. 272 

Composition of a Building 


Flue, Vent. 

. 252 

Construction 


Forms, Architectural. 

. 244 

Details of. 

268 

Fresh-Air Supply. 

. 252 

Floor . 

271 

Frieze .. 

. 217 

Materials of. 

25$ 



Corinthian Order. 

317 

G 


Cornice.217, 

268 



Box . 

268 

Ground, The. 

. 296 

Open . 

268 

Gutter .. 

. 270 


347 








































































348 


INDEX 


H 

Header . 

Hectograph Process. 

I 

India-Ink . 

Ionic Order. 

J 

Joists. 

L 

Lath and Plaster. 

Lettering 

Architectural . 

Spacing. 

Library . 

Lines 

Building . 

Dimension . 

Lining, Back. 

Lookout. 

M 

Materials of Construction... 
Muntins. 

O 

Office Building. 

Open Cornice. 

Openings, Location of. 

Orders, Use of the. 

Orders of Architecture. 

P 

Parting Strip. 

Pedestal . 

Pen and Ink Rendering. 

Perspective Sketches. 

Pivoted Windows. 

Plan, The. 

Planceer . 

Plank-Framed Windows.... 

Plaster . *... 

Plinth . 

Porch Construction. 

Preliminary Sketches. 

Primary Colors... 


R 

PAGE 


Pulley Stile. 296 

Rendering, Pen and Ink.... 305 

Reproducing Drawings. 238 

Riser .,. 285 

Roof Windows. 296 

S 

Sash . 289 

Scale Details. 227 

Schoolhouse . 220 

Section, The. 227 

Shades and Shadows. 259 

Shadows, Shades and.259 

Shaft. 217 

Shrinkage ... .. 277 

Sill . 296 

Single-Light Windows. 288 

Sketches 

Perspective. 203 

Preliminary . 194 

Sketching . 298 

Fundamental Principles... 298 

Method . 301 

Soffit. 269 

Staff-Head . 296 

Stairs. 284 

Stile, Pulley. 296 

Stock Doors. 279 

Stool . 296 

Strip, Parting. 296 

Sub-Jamb . 296 

Symbols, Architectural. 244 

T 

Threshold . 280 

Tracing Cloth. 243 

Transom . 289 

Tread . 285 

Treatment of Elevations.... 221 

Tuscan Order. 317 

Types of Buildings.220 

U 

Under-Floor . 272 

Use of the Orders. 216 

V 

Veneer. 279 


PAGE 

, 273 

, 240 

310 

317 

272 

274 

325 

328 

220 

249 

249 

296 

269 

255 

289 

220 

268 

226 

216 

317 

296 

217 

305 

203 

289 

206 

269 

290 

274 

217 

280 

194 

317 





































































INDEX 


349 


W 

PAGE 

Warehouse . 221 

Wash Drawings. 310 

Method . 310 

Water-Table. 217 

Water-Colors.305, 310 

White-Printing . 239 

Windows .288, 296 


PAGE 


Bay . 296 

Casement . 289 

Double-Hung . 289 

Pivoted . 289 

Plank-Framed . 290 

Roof. 296 

Single-Light. 288 

Working Drawings.206 























* 























* 


































